simulacrum of thought OpenAI releases new simulated reasoning models with full tool access New o3 model appears "near-genius level," according to one doctor, but it still makes mistakes. Benj Edwards – Apr 16, 2025 6:21 pm | 3 Credit: Floriana via Getty Images Credit: Floriana via Getty Images Story text Size Small Standard Large Width * Standard Wide Links Standard Orange * Subscribers only   Learn more On Wednesday, OpenAI announced the release of two new models—o3 and o4-mini—that combine simulated reasoning capabilities with access to functions like web browsing and coding. These models mark the first time OpenAI's reasoning-focused models can use every ChatGPT tool simultaneously, including visual analysis and image generation. OpenAI announced o3 in December, and until now, only less capable derivative models named "o3-mini" and "03-mini-high" have been available. However, the new models replace their predecessors—o1 and o3-mini. OpenAI is rolling out access today for ChatGPT Plus, Pro, and Team users, with Enterprise and Edu customers gaining access next week. Free users can try o4-mini by selecting the "Think" option before submitting queries. OpenAI CEO Sam Altman tweeted that "we expect to release o3-pro to the pro tier in a few weeks." For developers, both models are available starting today through the Chat Completions API and Responses API, though some organizations will need verification for access. "These are the smartest models we've released to date, representing a step change in ChatGPT's capabilities for everyone from curious users to advanced researchers," OpenAI claimed on its website. OpenAI says the models offer better cost efficiency than their predecessors, and each comes with a different intended use case: o3 targets complex analysis, while o4-mini, being a smaller version of its next-gen SR model "o4" (not yet released), optimizes for speed and cost-efficiency. OpenAI says o3 and o4-mini are multimodal, featuring the ability to "think with images." Credit: OpenAI What sets these new models apart from OpenAI's other models (like GPT-4o and GPT-4.5) is their simulated reasoning capability, which uses a simulated step-by-step "thinking" process to solve problems. Additionally, the new models dynamically determine when and how to deploy aids to solve multistep problems. For example, when asked about future energy usage in California, the models can autonomously search for utility data, write Python code to build forecasts, generate visualizing graphs, and explain key factors behind predictions—all within a single query. OpenAI touts the new models' multimodal ability to incorporate images directly into their simulated reasoning process—not just analyzing visual inputs but actively "thinking with" them. This capability allows the models to interpret whiteboards, textbook diagrams, and hand-drawn sketches, even when images are blurry or of low quality. That said, the new releases continue OpenAI's tradition of selecting confusing product names that don't tell users much about each model's relative capabilities—for example, o3 is more powerful than o4-mini despite including a lower number. Then there's potential confusion with the firm's non-reasoning AI models. As Ars Technica contributor Timothy B. Lee noted today on X, "It's an amazing branding decision to have a model called GPT-4o and another one called o4." Vibes and benchmarks All that aside, we know what you're thinking: What about the vibes? While we have not used 03 or o4-mini yet, frequent AI commentator and Wharton professor Ethan Mollick compared o3 favorably to Google's Gemini 2.5 Pro on Bluesky. "After using them both, I think that Gemini 2.5 & o3 are in a similar sort of range (with the important caveat that more testing is needed for agentic capabilities)," he wrote. "Each has its own quirks & you will likely prefer one to another, but there is a gap between them & other models." During the livestream announcement for o3 and o4-mini today, OpenAI President Greg Brockman boldly claimed: "These are the first models where top scientists tell us they produce legitimately good and useful novel ideas." Early user feedback seems to support this assertion, although until more third-party testing takes place, it's wise to be skeptical of the claims. On X, immunologist Dr. Derya Unutmaz said o3 appeared "at or near genius level" and wrote, "It's generating complex incredibly insightful and based scientific hypotheses on demand! When I throw challenging clinical or medical questions at o3, its responses sound like they're coming directly from a top subspecialist physicians." OpenAI benchmark results for o3 and o4-mini SR models. Credit: OpenAI So the vibes seem on target, but what about numerical benchmarks? Here's an interesting one: OpenAI reports that o3 makes "20 percent fewer major errors" than o1 on difficult tasks, with particular strengths in programming, business consulting, and "creative ideation." The company also reported state-of-the-art performance on several metrics. On the American Invitational Mathematics Examination (AIME) 2025, o4-mini achieved 92.7 percent accuracy. For programming tasks, o3 reached 69.1 percent accuracy on SWE-Bench Verified, a popular programming benchmark. The models also reportedly showed strong results on visual reasoning benchmarks, with o3 scoring 82.9 percent on MMMU (massive multi-disciplinary multimodal understanding), a college-level visual problem-solving test. OpenAI benchmark results for o3 and o4-mini SR models. Credit: OpenAI However, these benchmarks provided by OpenAI lack independent verification. One early evaluation of a pre-release o3 model by independent AI research lab Transluce found that the model exhibited recurring types of confabulations, such as claiming to run code locally or providing hardware specifications, and hypothesized this could be due to the model lacking access to its own reasoning processes from previous conversational turns. "It seems that despite being incredibly powerful at solving math and coding tasks, o3 is not by default truthful about its capabilities," wrote Transluce in a tweet. Also, some evaluations from OpenAI include footnotes about methodology that bear consideration. For a "Humanity's Last Exam" benchmark result that measures expert-level knowledge across subjects (o3 scored 20.32 with no tools, but 24.90 with browsing and tools), OpenAI notes that browsing-enabled models could potentially find answers online. The company reports implementing domain blocks and monitoring to prevent what it calls "cheating" during evaluations. Even though early results seem promising overall, experts or academics who might try to rely on SR models for rigorous research should take the time to exhaustively determine whether the AI model actually produced an accurate result instead of assuming it is correct. And if you're operating the models outside your domain of knowledge, be careful accepting any results as accurate without independent verification. Pricing For ChatGPT subscribers, access to o3 and o4-mini is included with the subscription. On the API side (for developers who integrate the models into their apps), OpenAI has set o3's pricing at $10 per million input tokens and $40 per million output tokens, with a discounted rate of $2.50 per million for cached inputs. This represents a significant reduction from o1's pricing structure of $15/$60 per million input/output tokens—effectively a 33 percent price cut while delivering what OpenAI claims is improved performance. The more economical o4-mini costs $1.10 per million input tokens and $4.40 per million output tokens, with cached inputs priced at $0.275 per million tokens. This maintains the same pricing structure as its predecessor o3-mini, suggesting OpenAI is delivering improved capabilities without raising costs for its smaller reasoning model. Codex CLI OpenAI also introduced an experimental terminal application called Codex CLI, described as "a lightweight coding agent you can run from your terminal." The open source tool connects the models to users' computers and local code. Alongside this release, the company announced a $1 million grant program offering API credits for projects using Codex CLI. A screenshot of OpenAI's new Codex CLI tool in action, taken from GitHub. Credit: OpenAI Codex CLI somewhat resembles Claude Code, an agent launched with Claude 3.7 Sonnet in February. Both are terminal-based coding assistants that operate directly from a console and can interact with local codebases. While Codex CLI connects OpenAI's models to users' computers and local code repositories, Claude Code was Anthropic's first venture into agentic tools, allowing Claude to search through codebases, edit files, write and run tests, and execute command line operations. Codex CLI is one more step toward OpenAI's goal of making autonomous agents that can execute multistep complex tasks on behalf of users. Let's hope all the vibe coding it produces isn't used in high-stakes applications without detailed human oversight. Benj Edwards Senior AI Reporter Benj Edwards Senior AI Reporter Benj Edwards is Ars Technica's Senior AI Reporter and founder of the site's dedicated AI beat in 2022. He's also a tech historian with almost two decades of experience. In his free time, he writes and records music, collects vintage computers, and enjoys nature. He lives in Raleigh, NC. 3 Comments

Health It is harder for our bodies to absorb key nutrients from plant-based foods, so some vegans may be short on essential amino acids for healthy muscles and bones despite eating plenty of protein 16 April 2025 It isn’t necessarily easy to absorb important amino acids from vegan foodsSolStock/Getty Images While most vegans eat enough protein, it seems many fall short on essential amino acids such as lysine and leucine, according to a new study. The finding suggests vegans may need to be more careful about the kind of protein in their diet, not just the quantity they consume. Patricia Soh at the Riddet Institute in Palmerston North, New Zealand, and her colleagues analysed the diets of 193 adults living in New Zealand who had been vegan for at least two years prior to the study.…

The popular UPPABaby stroller will go from $899 to $1199 due to tariffs. Fly View Productions/Getty Images 2025-04-16T22:07:27Z Save Saved Read in app This story is available exclusively to Business Insider subscribers. Become an Insider and start reading now. Have an account? UPPAbaby brand strollers and car seats are going to cost parents more because of tariffs, one store owner tells me. Elizabeth Mahon, the owner of a baby goods store in Washington, DC, is raising prices on one stroller by $300. UPPAbaby says it's trying to absorb increased costs of production, but calls price hikes "unavoidable." Parents, get ready: It looks like it's going to get a lot more expensive to raise a family — and some places are already raising prices, like one baby and toy store in Washington, DC.I talked to Elizabeth Mahon, the owner of Three Littles, which she's run since 2019. She told me price hikes are on the way, and she said they're because of Donald Trump's tariffs.She said she'd have to raise prices on items that are manufactured mostly in China, like the popular UPPAbaby Vista stroller, which will now cost $1,199 — up from $899.Massachusetts-based UPPAbaby has said it's passing the increased costs of production onto customers. "Please know that we've made every effort behind the scenes to absorb as much of the cost as possible," the company said in a statement on its Instagram, "but some price increases are unfortunately unavoidable."Mahon told me how tariffs are already affecting her store and her customers. And about her biggest worry: that some families won't be able to afford necessities like car seats at all.(This interview has been edited for length and clarity).Business Insider: So what's going on with the price hikes with strollers and car seats?Elizabeth Mahon: Nuna and UPPAbaby both reached out about a week ago and said, "Hey, this is going to be a new price list moving forward."Then, on Monday, we got another email from UPPAbaby with an amended price list. When they first emailed, it was when tariffs were at 54% and now tariffs are 145% — they had to fix the prices to better reflect the current tariffs.Is this across the whole range of things? Strollers, car seats, accessories? Yes, pretty much everything is going up in price. Initially, a lot fewer items were included in these price increases. There were still price increases, but they weren't as drastic or far-reaching. And now, the prices of just about everything that they manufacture have to go up.So the UPPABaby Vista stroller, which is about $900 for the base model — that's going up about $300. It's basically like a 33% increase. Is that about what you're seeing across the board? 33%?It depends. Some things are going up 20%, some things are going up 40%. It just depends. But 30% is, I would say, the average.Have you heard from other manufacturers about tariff increases in other categories? Clothing, toys, books?A ton. I've been getting a phone call or an email a day from our vendors letting us know that the prices are increasing. We've received a couple of emails from vendors telling us that they will no longer even be able to entertain a wholesale program.I do know that some other stroller and car seat brands are chatting about what it would look like to sell exclusively online. This would be a huge detriment to families because they won't be able to test them out in person.What are you hearing from your customers?I think there's a lot of panic buying. People are hurrying up to buy car seats that maybe they don't need yet because they are worried about these price increases. We've been talking to a lot of customers who are considering buying for children they don't even have yet so that they can get these prices.I would be remiss not to acknowledge that we have a shop in a community where there's a lot of privilege.I've heard a lot on social media that these price hikes aren't going to deter people who are shopping for these more expensive brands. But I absolutely disagree. I've heard daily from people who have said, "This stroller at $899 was already a huge splurge for me, and $1,200 is just too far out of my price range."Beyond that, the bigger conversation I think is that there are going to be many families who just cannot afford a stroller for their kids or a car seat for their child, period. Even the lower-end products — there is no option to just buy exclusively American.There is no option to just not use a car seat. You have to have it, but we're going to see price increases across every brand no matter what if they're manufactured in China.With car seats, that's the kind of item that — unlike strollers — it's really recommended you don't get one used, right?Absolutely. I am a child passenger safety technician, and we just would never recommend getting a secondhand car seat because there is no way to prove that that car seat has not been in a crash, which makes it no longer safe to use.As a small-business owner, how will these price increases affect your bottom line?I've just had to make some really big decisions already and spend money that we didn't really have to spend on extra inventory because these tariff hikes and the hysteria surrounding these new inflated prices are causing a lot of people to buy.There are going to be a lot of gaps where people aren't going to be able to buy things when they need them. That's because people are buying convertible car seats today for kids who won't fit in it for a year. The people who need that car seat now might not be able to get it because it's sold out. The manufacturing facilities can't produce at a faster rate than they had already planned on, or they don't have the materials, or they don't have the money, or they're trying to navigate the tariffs.Are you worried about what will happen having to pass on the prices to customers if that will turn customers away from your store?Absolutely. We already have customers who will come into the shop and demo the products we have and then come back in and tell us they bought them secondhand. And that's everyone's prerogative. I totally understand why people do that. The baby industry is expensive and the products we sell are on the higher-end. But I think that we'll be starting to see a lot more of that.I do think we'll see the resale market inching up higher, which will make some of these products that people used to be able to buy secondhand unaffordable, too.Even more than business, I'm worried that there are going to be families that aren't able to get seats for their children at all because they can't afford them. Recommended video

This story appeared in The Logoff, a daily newsletter that helps you stay informed about the Trump administration without letting political news take over your life. Subscribe here.Welcome to The Logoff: Today I’m focusing on two federal judges threatening to hold the Trump administration in contempt, escalating a conflict between the president and the courts with major implications for the balance of power in our republic.What’s the latest? Judge James Boasberg said today that, if President Donald Trump’s team does not give the dozens of Venezuelan men sent to a Salvadorian prison a chance to legally challenge their removal, he’ll begin contempt proceedings against the administration. In March, Boasberg ordered the administration to halt the deportation flights — and to turn around any planes that had already taken off. The administration did not comply.In a separate case, Judge Paula Xinis demanded Tuesday that the administration answer questions about why it was not complying with a Supreme Court order to “facilitate” the release of a man who was — by the administration’s own admission — sent to a Salvadorian prison via an “administrative error.” Kilmar Armando Abrego Garcia’s lawyers are asking the court to hold the administration in contempt, but Xinis said she first wanted to review its responses.What’s next? A Trump spokesperson said today that the administration would appeal Boasberg’s ruling. In the Xinis case, the administration has two weeks to comply with the judge’s request for answers.What happens if a judge finds the administration in contempt of court? The judicial branch largely relies on the executive branch to enforce its decisions, including imposing consequences for contempt of court. But what happens when you ask the executive branch — and particularly this executive branch — to impose consequences on itself? That’s not clear.What’s the big picture? Do judges have the power to compel the administration to change its behavior? The results of these two cases will go a long way toward providing an answer to that crucial question. And if that answer is “no,” then the single most powerful check on Trump’s power will be greatly diminished.And with that, it’s time to log off…I really enjoyed this interview with Tina Fey, both because she’s a tremendously entertaining and innovative thinker and because she’s a living reminder that we can find joy in difficult times. Thanks so much for reading, and I’ll see you back here tomorrow.You’ve read 1 article in the last monthHere at Vox, we're unwavering in our commitment to covering the issues that matter most to you — threats to democracy, immigration, reproductive rights, the environment, and the rising polarization across this country.Our mission is to provide clear, accessible journalism that empowers you to stay informed and engaged in shaping our world. By becoming a Vox Member, you directly strengthen our ability to deliver in-depth, independent reporting that drives meaningful change.We rely on readers like you — join us.Swati SharmaVox Editor-in-ChiefSee More:

The just-ended Daredevil: Born Again focuses on Matt Murdock’s ongoing clash with the Kingpin, but it’s another major rogue that sets things in motion. Minutes into the pilot, Wilson Bethel’s Bullseye shows up, kills Foggy with a single gunshot, and proceeds to wreak havoc inside of Josie’s Bar. When he’s not throwing a lot of knives at Daredevil, he’s throwing knives into civilians, knocking them out with cue balls to the skull, or just punching them in the stomach. Many of these could’ve been easily bypassed while still keeping Daredevil on his toes, but among his many skills and traits, ol’ Bullseye is vindictive and such a hater. To be a Marvel fan is to have mixed feelings about the MCU’s villain output. For every Killmonger or Vulture, you’ve got a Cassandra Nova, Iron Monger, or whatever Kang was teed up to be. After a certain point, the baddies stopped being simple foils for the good guys and became saddled with attempts at being topical or thematically relevant in some respect. This can work, but too often it’s left projects feeling scattered or confused. For many, the most recent example will be Captain America: Brave New World’s Leader and Red Hulk, but there’s also the Skrulls, Thanos, and Falcon & the Winter Soldier’s double dose of John Walker and Karli Morgenthau. This is a problem that goes beyond a single franchise—it might extend to all blockbuster action movies in the last 20 years—but Marvel’s been the worst at it for sure. And yet, the current slate of MCU projects has featured some memorable haters among their ranks. Much of this has come from TV: both Daredevil shows have avoided this in part by just letting Bullseye, Kingpin, and Fisk’s wife Vanessa be some of the most evil, mean people in all of New York. All three are victims to one degree or another, but both the original Daredevil and Born Again have stopped short of making them overly sympathetic or trying to distance them from their previously bad actions. The Fisk who loves Vanessa like she’s the only woman in the world is the same man who locked her lover in a cage, decapitated a man with a car door, and crushed another man’s head with his bare hands. Vanessa, who loves her husband just as much, viewed his years-long departure as a betrayal on par with her father cheating on her mother—yet she still orchestrated Foggy’s death and shot her lover dead like it was nothing. © Marvel Studios The same is true of Ben Poindexter, aka Bullseye, maybe the most broken person in Daredevil’s assortment of characters. Yes, he’s forever wedded to those two as they deploy him like an attack dog, which sometimes ends with him getting thrown off a building or his spine broken. But he likes what he does and has fun messing with Matt, either by wearing his costume or throwing anything in the room at him when they fight—how can the guy not get a kick out of this when he can kill a fly with a paper clip or toss a gun at someone’s head without looking? These contrasts help make these characters compelling while also keeping them true to themselves as they test Matt’s resolve and patience. Outside of Born Again, Marvel’s found another successful hater villain in Your Friendly Neighborhood Spider-Man’s take on Scorpion. For whatever reason—maybe he’s not as visually dynamic as other heavy hitters—he hasn’t been given his own spotlight like Spider-Man’s A-list baddies Doctor Octopus, Green Goblin, or Venom. Over the past decade, Mac Gargan has come part of a larger set; Insomniac’s Spider-Man games made him part of the Sinister Six (and later paired him with Rhino), and his one live-action appearance in Spider-Man: Homecoming seemed ready to continue that trend in a hypothetical sequel. Friendly Neighborhood’s solution? Individualize the two most well-known incarnations but make them equally formidable. Gargan is introduced in the show as the leader of an emerging gang called the Scorpions making trouble for the One-Tenth, and his eventual successor Carmilla Black as his second-in-command. There’s not much nuance to them, but they make up for it in presence. Carmilla’s introduced as a problem Lonnie and the One-Tenth will have to deal with eventually, but she pales in comparison to Gargan, who’s not just a hater, but a complete demon. A scary guy is even scarier in an armored suit with a stinger tail, and he kills and terrorizes the city like he’s finally found his calling in life. In Gargan, the show’s creative team channels the same energy Homecoming did with its shovel talk scene between Peter and Vulture. Friendly Neighborhood seems to have a bright future ahead of it, and with luck, Gargan and Black will pop up every now and then to put Peter and any other potential heroes through their paces. Now all we need is for that energy to extend over to the movies. Captain America: Brave New World took some steps in that direction with Giancarlo Esposito’s Sidewinder, who just wants to kill Sam, whether he gets paid or not. Their beef and subsequent brawls are enough to make you wish that was just the whole movie, and speaks to what makes hero/villain rivalries engaging when done well. Such a personal, ongoing fight is more interesting than a villain who thinks they’re a hero or working toward some grand plan set to pay off years later, and it’s something the MCU’s conveyor belt of projects could stand to have more of, regardless of the medium. Want more io9 news? Check out when to expect the latest Marvel, Star Wars, and Star Trek releases, what’s next for the DC Universe on film and TV, and everything you need to know about the future of Doctor Who.

Although the magnetic field of Mars hasn’t been in effect for billions of years, the evidence it left behind may suggest that the planet’s core is entirely liquid. Magnetic imprints still exist on Mars, but they’re centered around its southern half, raising a mystery that has left scientists scratching their heads for years. Recent research, however, has proposed a promising answer: the molten Martian core likely generated a magnetic field that only covered the Red Planet’s southern hemisphere.A new study published in the journal Geophysical Research Letters offers an overhauled perspective on Mars’ magnetic field, which dissipated around 4 billion years ago. This theory shows how Mars, despite sharing a few similarities with Earth, has a much different history full of unexpected surprises. How Did Mars Lose Its Magnetic Field?The history of magnetism on Mars remains a critical field of study since it is closely tied to the planet’s potential capacity for life billions of years ago. Mars’ magnetic field was once generated by its dynamo, a mechanism shaped by currents within the planet’s liquid core (thought to be made of iron, sulfur, and hydrogen). The magnetic field would have protected Mars from space radiation and solar wind, just like Earth’s magnetic field does for our planet today. But why did Mars lose its magnetic field while Earth still has one? It may have something to do with the Martian core cooling down, causing its dynamo to collapse. Afterwards, the planet’s oceans vanished, as did any forms of life that lived there.Simulating a Liquid CoreThe new study indicates that Mars’ magnetic field may not have been entirely similar to Earth’s because of the planet's presumably liquid core. “The logic here is that with no solid inner core, it’s much easier to produce hemispheric (one-sided) magnetic fields,” said lead author Chi Yan, a research associate at the University of Texas Jackson School of Geosciences, in a statement. “That could have implications for Mars’ ancient dynamo and possibly how long it was able to sustain an atmosphere.”Researchers got the idea to simulate a fully liquid core from NASA’s InSight lander, which landed on Mars in 2018 and found that its core consisted of elements that were lighter than expected. This points to the whole Martian core being molten — Earth’s core, on the other hand, is made up of a solid inner core and a liquid outer core.  A One-Sided Magnetic Field Influenced by the InSight findings, the researchers created simulations of early Mars with a liquid core. They ran the simulations a dozen times on supercomputers, making the planet’s northern half of the mantle hotter than the south with each successive test.Eventually, this revealed that heat from the core would escape at the southern end of Mars, generating a strong magnetic field that only encompassed the southern hemisphere.“We had no idea if it was going to explain the magnetic field, so it's exciting to see that we can create a (single) hemispheric magnetic field with an interior structure that matches what InSight told us Mars' interior is like today,” said co-author Sabine Stanley, a physicist at Johns Hopkins University, in a statement.This theory of a one-sided magnetic field stands in stark contrast to prior theories stating that asteroid impacts were responsible for destroying evidence of a planet-wide magnetic field on the northern hemisphere. The breakdown of Mars’ magnetic field ultimately made the planet inhospitable. Although much of the planet's history is still undetermined, the magnetism displayed early in its existence may yet hold further answers on a bygone era when Martian life may have been possible. Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:Geophysical Research Letters. Mars' Hemispheric Magnetic Field From a Full-Sphere DynamoThe Harvard Gazette. Life on Mars?Jack Knudson is an assistant editor at Discover with a strong interest in environmental science and history. Before joining Discover in 2023, he studied journalism at the Scripps College of Communication at Ohio University and previously interned at Recycling Today magazine.

We may earn revenue from the products available on this page and participate in affiliate programs. Learn more › Portable saunas provide all the sweat-inducing benefits of their stationary siblings without the pain of permanent installation. After extensive research and hands-on testing, we found the SereneLife Full Portable Sauna to be the best overall balance of performance, portability, and price. But these contraptions aren’t one-size-fits-all. The best portable sauna for you fits your specific home, needs, and budget. Best overall: SereneLife Full Portable Sauna  Best splurge: SaunaSpace Luminati Portable Infrared Sauna Best infrared: Heat Wave Radiant Saunas Oversized Portable Cabin Best for stress: Sun Home Saunas Infrared Sauna Blanket Best for travel: LifePro Far Infrared Sauna Blanket Best for home: Clearlight Curve Sauna Dome Best small: HigherDose Infrared Sauna Blanket Best budget: Durasage Oversized Portable Steam Sauna How we chose the best portable saunas Portable saunas come in an array of styles, and we wanted to reflect this diversity while being mindful of price and durability. We searched through dozens of portable sauna products and narrowed down our list to include ones that are the highest quality possible within their price range. For example, we wanted to ensure the budget option came with a warranty in case any of the components fail.  When selecting the best portable saunas, we also considered the materials and power output to find energy-efficient options that won’t send your power bill skyrocketing. We also considered whether or not the portable sauna was aesthetically pleasing because it will become a staple in your home.  During our review process, we scoured reviews across multiple sites. Once we decided on a product, we cross-referenced multiple sites and retailers to ensure the product stood up to dozens of user reviews. Best portable saunas: Reviews & Recommendations Once relegated to the realm of gyms and spas, saunas have exploded in popularity as medical studies have demonstrated that they can relieve pain and promote relaxation. The best portable saunas should make it easy to bring some heat and healing into your home—not cause more stress. After scouring, sourcing, and performing lots of testing, here’s what we found. Best sauna kit: SereneLife Full Portable Sauna  SereneLife Full Portable Sauna  Pros Full-size design allows you to reap full-body benefits  Heats up to 140 degrees Fahrenheit  Packable design lets you stow away when not in use Cons Set-up instructions can be confusing Taller people may not be able to fully stand inside  Specs Dimensions: 35.4” x 35.4” x 70.9” Weight: 37 pounds Materials: Cloth, plastic Why it made the cut: This portable sauna is tall enough for most adults to stand up in, creating a more comfortable home sauna experience than its competitors.  As one of the only full-sized, fully portable saunas on the market at this price point, the SereneLife is at the top of our list for best portable sauna kit. While most portable saunas require you to stick your head and neck out of a hole at the top, this is completely enclosed so you can get the infrared benefits on your face, head, and neck. It comes with a folding chair so you can sit comfortably inside and a heating pad for your feet.  After you set up this sauna for the home, just set your desired temperature and timer up to 60 minutes on the remote. It takes a while to heat up, but once it gets going, it can reach temps around 140 degrees Fahrenheit, mimicking your favorite gym sauna. Additionally, this model comes in both infrared and steam versions, depending on the type of heat you prefer.  Best overall: SaunaSpace Luminati Portable Infrared Sauna SaunaSpace Luminati Portable Infrared Sauna Pros Aesthetic design so you don’t need to break down after each use  Walk-in style provides a full-body experience High-quality, durable materials that are backed by a 10-year warranty  Cons Heavy and may take two people to set up The high price tag might be a deterrent for some buyers  Specs Dimensions: 52” x 52” x 63” Weight: 50.3 pounds Materials: North American basswood, bamboo, stainless steel, and canvas Why it made the cut: This beautifully designed, minimalist sauna is made of high-quality materials and creates a pleasant environment. Part of the sauna experience is the atmosphere: the lack of visual distractions and the smell of untreated wood. And this portable, full-body sauna allows you to immerse yourself in a relaxing environment. The wooden components, like the base and the stool, bring in elements of a traditional sauna without the heavy weight and elaborate installation. While some infrared saunas come with the risk of EMF exposure, SaunaSpace uses advanced technology to keep these levels low. (While some people may prefer to limit their exposure to EMFs, no research exists to support that low levels of exposure are harmful.)  The high-quality, sustainable materials take this personal sauna above and beyond the competition. The canvas comes in multiple colors—like indigo, stone, and hand-dyed turmeric—so you can match this sauna kit with your current wall color or room’s aesthetic. Although it is more expensive than most portable saunas, it is a beautiful, well-crafted addition to a home and comes with a 10-year warranty. If after the 100-day trial period you’re not satisfied, you can return it for a full refund.  Best infrared: Heat Wave Radiant Saunas Oversized Portable Cabin Pros Roomy for a sit-in design sauna  Incredibly energy efficient All the components feel high quality and are backed by a 1-year warranty Cons Pricier than similar products  Maximum timer length is 30 minutes  Specs Dimensions: 33.5″ x 33″ x 41. 5″ Weight: 24 pounds Materials: Polyester and beech Why it made the cut: It’s energy-efficient, spacious enough for people up to 6’5”, and portable enough to use for car travel.  Tent-style portable saunas may look goofy, but they’re ideal for those with minimal space or people who want a lightweight option. This home sauna has a sturdy frame that makes it easy to get in and out, interior zippers for your hands, and a pocket for the handheld remote or a phone. Using the remote, you can control the temperature for both the sauna and foot pad, and set the low-EMF carbon fiber heating panels up to 150 degrees Fahrenheit.  The set-up and break-down processes take less than a minute, and the carrying handle makes transport easy so you can find relaxation anywhere. Plus, the quilted polyester fabric is moisture-resistant and looks nicer than many of the tent-style saunas. The complete sauna kit comes with two soft neck collars for optimal comfort and a padded floor mat that will help soak up moisture when the sweat builds. Although this personal sauna is on the higher end of the price range for his style, you’ll save money on power bills because of the energy-efficient carbon heating panels.  Best for stress: Sun Home Saunas Infrared Sauna Blanket Pros Wide range of temperature and timer settings Multiple colors Backed by a 1-year warranty Cons Expensive Specs Dimensions: 71” x 71” unfolded Weight: 15 pounds Materials: Waterproof polyurethane Why it made the cut: This blanket is easy to set up and easy on the eyes, thanks to fun patterns and colorways. Bringing the spa experience to your living room doesn’t have to be boring. Take the Sun Home Saunas Infrared Sauna Blanket, which comes in a jazzy blue zebra print (pictured), a fun purple and red colorway, and a classic black style. The climate and timer controls are easy to use: Temperature settings range from 35-75℃, and time settings range from 30-60 minutes. Pre-heat time only takes around 15 minutes. The industrial-grade Velcro keeps the heat in and feels sturdy to the touch. However, the blanket is easy to open—making cleaning a breeze. And, its large interior circumference will make you feel cozy—not constricted. When you’re done using it, simply pack it away in the included carrying case. Best for travel: LifePro Far Infrared Sauna Blanket Pros Folds into an included canvas carrying bag Includes disposable sauna wraps for increased temperature Waterproof fabric makes for easy cleaning Cons Not very hot at lower settings Moderate size when stowed in bag Specs Dimensions: 70.8 inches L x 70.8 inches W Weight: 13 pounds Materials: Waterproof Oxford cloth, polyurethane leather, and cotton Why it made the cut: The LifePro Rejuvawrap packs a sauna’s catharsis into a full-body blanket, making it a good choice for your mobile detox needs. If you’re looking to take the benefits of your portable sauna on the road, the LifePro Rejuvawrap is a sleeping bag-style sauna blanket that’s definitely worth considering. Its foldable five-layer design consists of a far-infrared carbon fiber heating pad, two layers of comfortable cotton, and a waterproof oxford cloth topper to aid with sweat cleanup. Using an integrated remote, users can adjust the blanket temperature and auto-shutoff timer between 95-176 degrees Fahrenheit and 5-60 minutes. The Rejuvawrap does take a while to heat up, and though many users have reported that only its higher settings feel sufficiently hot, we actually like the blanket’s ability to offer everything from soothing warmth to blazing heat. If you find yourself needing even more focused heat, the Rejuvawrap also includes a handful of disposable sauna wraps and a washable towel to further tailor your sauna experience. Like other sauna blankets, the LifePro Rejuvawrap is fairly bulky when folded and stored in its canvas carrying bag, but we still found it to be easy  to tote around and stow in a car or closet. Best for home: Clearlight Curve Sauna Dome Clearlight Curve Sauna Dome Pros Memory foam pad is super plush and comfy Low-EMF infrared heat  Comfortable, reclined design is great for users who can’t sit for long periods Cons Not as portable and space-efficient as others on this list  Very heavy  Specs Dimensions: 69” x 28” x 18” Weight: 80 pounds Materials: Organic hemp cloth, wood, memory foam Why it made the cut: Achieve full relaxation mode in this personal lay-down sauna.  Not everyone has the space, money, or time for a full-scale sauna installation. But that doesn’t mean you have to sacrifice quality. The Curve Sauna Dome allows for a high-quality experience without the hassle of a permanent home sauna. With a memory foam infrared pad and multiple heat level adjustments, this indoor sauna is one of the most comfortable options on our list. Simply set the timer, lay down, and relax. When you’re finished, slide the two domes together for easy storage.  The model uses far-infrared light, known for its wellness benefits, including increased circulation and boosted immunity. It also comes with a lifetime warranty, so you can buy in confidence knowing your purchase is protected. However, this sauna is a more serious investment than others on this list: it’s heavier, less space-efficient, and not travel-friendly.  Best small: HigherDose Infrared Sauna Blanket HigherDose Infrared Sauna Blanket Pros Short pre-heat time of 10 minutes  Non-toxic materials Fully adjustable with a handheld controller  Cons Maximum interior circumference of 65 inches may be too small for some users Requires more frequent cleaning Specs Dimensions: 71” x 71” Weight: TK pounds Materials: Waterproof Polyurethane and fireproof cotton Why it made the cut: Just about everything is better in bed, and sauna sessions are no exception. If the thought of being trapped inside a pop-up structure with your head sticking out the top gives you the heebie-jeebies, the HigherDose Sauna Blanket is the answer. This sauna bag provides all the benefits of a portable sauna, yet is thin, lightweight, and convenient. You can use it on any heat-resistant surface like your bed or a yoga mat, and you have the choice of wearing a layer of clothing or using HigherDose’s towel insert. However, you can expect to sweat a lot, so the manual emphasizes the importance of preventing any skin-to-mat action.  This product is just really thoughtfully designed. Charcoal and clay layers beneath the infrared panels balance the heat. Of all the options, this is one of the easiest to store, which can come in very handy if you’re extremely limited on space. It also makes it one of the easiest models with which to travel. Best budget: Durasage Oversized Portable Steam Sauna Durasage Oversized Portable Steam Sauna Pros Two large pockets on the front can fit a tablet or book Great price  1.5-year warranty  Cons Chair is flimsy and can only support up to 20 lbs Clumsy frame design makes it hard to get in and out  Specs Dimensions: 31.5” x 33” x 41” Weight: 15.8 pounds Materials: Polyester and PVC tubing Why it made the cut: This affordable steam sauna leaves room in your budget for actually traveling. This portable, sit-in steam sauna is great if you just want to test the waters of a home sauna or don’t have the cash to make a bigger investment. With the pop-up sauna tent and a foldable chair, this sauna kit has everything you need to start a regular sauna routine. (However, you may want to replace the flimsy chair with one of your own. Just ensure you don’t need it for other purposes—it will get sweaty!) This portable sauna also has dual pockets for a book or e-reader and easy-to-zip hand slots.  We like the budget-friendly price tag, but what we love best about this portable sauna is that you can add fragrances like herbs or oil to the plastic container on the side of the steam generator. The scent of lavender or jasmine will elevate your experience, and you can’t do this with an infrared sauna. Things to consider when buying the best portable saunas Portable saunas come in three types of heat:  Dry saunas are the most traditional and use heating panels to warm the air without increasing the humidity. These saunas can reach higher temperatures than steam saunas.  Infrared saunas use infrared lighting panels to heat your body in an effort to aid muscle recovery. Because they use light to heat your body instead of heating the air around you, they generally don’t get as hot as traditional dry saunas (so you can spend more time in them). They’re a great option for sauna users who can’t tolerate the humidity of steam saunas or high temps of dry saunas.  Steam saunas use—you guessed it—steam to warm the air and allow you to work up quite a sweat. Unlike dry saunas, steam saunas use a heater with water to warm up your space. They take a bit longer to heat up but provide a more classic experience similar to Finnish steam rooms.  Design  You can find portable saunas that encapsulate your entire body or smaller options that you sit in from the neck down. If space isn’t an issue and you don’t get claustrophobic easily, you may want to choose a full-body personal sauna. However, the neck-down, collapsible saunas can be a great option for people who prefer to multitask and read a book while relaxing. If you deal with chronic pain and have trouble sitting upright for long periods of time, a reclined sauna or sauna blanket could be a good fit.  Size and weight Consider where you’re going to put your sauna and how often you’re going to use it. More spacious saunas will be more comfortable, especially for taller or larger users, but smaller saunas are better for saving space. If you plan to break it down after every use, you can opt for a foldable sauna with a larger footprint. Some portable saunas require a more elaborate setup and are best for users who aren’t ready to install a permanent indoor sauna but can leave a portable sauna up for longer periods of time.  FAQs Q: How much do portable saunas cost? Portable saunas cost between $100 and $3000 dollars, depending on the style, brand, and quality. If you want a reliable personal sauna, you should expect to spend at least $300, although you can find lower-quality options for cheaper. Q: What are the health benefits of a portable sauna? Portable saunas are known for their health and wellness benefits, including relaxation, improved circulation, pain relief, and reduced risk of disease, including hypertension. Research about sauna benefits used to be scant, but in the past five years, multiple studies have implied that sauna bathing can offer health and wellness benefits for many regular users.  Q: How long do portable saunas last? The lifespan of a portable sauna can vary widely. Just like any product, it depends on the quality of your purchase. While you can find dozens of budget options online, these may have a shorter lifespan than high-quality home saunas. Some portable saunas, like the Curve Sauna Dome, come with a lifetime warranty.  Final thoughts on the best portable saunas Best overall: SereneLife Full Portable Sauna  Best overall: SaunaSpace Luminati Portable Infrared Sauna Best infrared: Heat Wave Radiant Saunas Oversized Portable Cabin Best for stress: Sun Home Saunas Infrared Sauna Blanket Best for travel: LifePro Far Infrared Sauna Blanket Best for home: Clearlight Curve Sauna Dome Best small: HigherDose Infrared Sauna Blanket Best budget: Durasage Oversized Portable Steam Sauna For those who can afford it and have the dedicated space, the SaunaSpace Luminati is one of the best portable saunas available. The ThermaLight technology allows you to enjoy the benefits of infrared heat without the added risk associated with EMFs, and the organic canvas and bamboo components are minimal yet aesthetic enough to leave installed in the home.  

Nature, Published online: 16 April 2025; doi:10.1038/d41586-025-01106-ySex and gender research could lead to better, more equitable treatments — if it is allowed to continue without political interference.

Remnants of a liquid layer of magma near Earth's core, formed in the first few hundred million years of the planet's history, may still persist today as odd anomalies in the mantle.