OpenAI vs Anthropic: How the Two Biggest AI Labs Actually Compare

Summary: As of November 2026, Anthropic carries the higher last private valuation ($965 billion vs. OpenAI's $852 billion) and leads enterprise LLM API spend 55% to 31%, according to Menlo Ventures. OpenAI still dominates consumers, with ChatGPT above 900 million weekly users. Anthropic filed for a Nasdaq IPO under the ticker ANT on October 26, 2026.

Which company is actually winning the AI race, OpenAI or Anthropic? Two years ago the answer was obvious. Today it depends on which number you look at. Anthropic's public S-1 filing has turned the openai vs anthropic debate from guesswork into audited data, at least on one side. This breakdown compares the two companies on structure, valuation, revenue, products, API pricing, enterprise adoption, safety and compute, with every figure dated and sourced.

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The core difference between OpenAI and Anthropic is where each earns its money. OpenAI built the largest consumer AI product in ChatGPT and has expanded into business. Anthropic built Claude around enterprise and developer use, and it now leads business API spending. Both are public benefit corporations racing to build frontier models with very similar price ladders.

The table shows the two companies now sit closer together than their reputations suggest. The real split is audience: ChatGPT owns the consumer, while Anthropic has turned business API demand into the faster-growing revenue line. Figures come from the sources cited in each section below, and the full background on what Anthropic is covers the company's history in more depth.

OpenAI launched on December 11, 2015, with Sam Altman and Elon Musk as co-chairs, Greg Brockman as CTO and Ilya Sutskever as research director. Anthropic was founded in 2021 by a team of researchers and is led by co-founder and CEO Dario Amodei. Altman remains OpenAI's CEO as of November 2026.

OpenAI's original announcement lists a founding group that also included Andrej Karpathy, John Schulman and Wojciech Zaremba, backed by $1 billion in pledged funding from its founders and other backers. Anthropic's S-1 describes the company as "founded in 2021 by a team of researchers," with Amodei as chief executive officer and co-founder. Anthropic says it launched Claude publicly in the first quarter of 2023.

That head start matters less than it once did. Anthropic reached a valuation above OpenAI's roughly five years after its founding, while OpenAI took more than a decade to reach a comparable figure.

Both companies are now public benefit corporations, but control works differently. OpenAI's for-profit, OpenAI Group PBC, is controlled by the nonprofit OpenAI Foundation after an October 2025 recapitalization. Anthropic is a Delaware PBC whose Long-Term Benefit Trust elects a group of directors that will form a majority of its board.

OpenAI completed its restructuring on October 28, 2025. According to OpenAI's structure announcement, the renamed OpenAI Foundation held equity then valued at about $130 billion. Under the revised Microsoft agreement signed the same day, Microsoft holds roughly 27% of OpenAI Group PBC on an as-converted diluted basis, a stake valued at about $135 billion at the time.

Anthropic's S-1 registration statement states its public benefit as "the responsible development and maintenance of advanced AI for the long-term benefit of humanity." The Long-Term Benefit Trust, described as "financially disinterested trustees," elects Class T directors through a special class of stock. Anthropic has since filed an amended S-1 (Form S-1/A) with the SEC.

The IPO paths have split. Anthropic announced its public S-1 filing on October 26, 2026, for a listing on the Nasdaq Global Select Market, with Goldman Sachs and Morgan Stanley leading. OpenAI confirmed in June 2026 that it had "recently submitted a confidential S-1," per eWeek, but Altman told Fortune in September: "I would say not 2026." The Anthropic IPO guide and the OpenAI IPO timeline track both listings as they develop.

The governance difference is practical, not cosmetic. A public Anthropic will publish quarterly results, while OpenAI's finances will stay mostly private until it lists, so comparisons for the next year will rely on audited numbers for one company and company statements for the other.

Anthropic is worth more on paper. Its $65 billion Series H on May 28, 2026, set a $965 billion post-money valuation. OpenAI's most recent disclosed round, $122 billion in committed capital closed March 31, 2026, valued it at $852 billion post-money. Both figures are private marks, not public market prices. In early November 2026, OpenAI was reported to be raising a new round of up to $20 billion at a $1.25 trillion post-money valuation, according to the Financial Times and CNBC as summarized by The Next Web; that round had not closed at the time of writing.

OpenAI says its round was anchored by Amazon, NVIDIA and SoftBank and included more than $3 billion from individual investors, per its funding announcement. Anthropic's Series H announcement names Altimeter Capital, Dragoneer, Greenoaks and Sequoia Capital as leads. The S-1 adds that Anthropic had raised an aggregate $141.1 billion as of June 30, 2026.

Anthropic's valuation rose about 2.5 times in roughly three and a half months, from $380 billion on February 12 to $965 billion on May 28, 2026. Over the same stretch, its stated run-rate revenue climbed from $14 billion to more than $47 billion, which suggests investors were pricing growth speed more than current size. Reuters has reported that Anthropic could carry a market value of around $1.5 trillion at listing, a figure cited by IPOScoop that the company has not confirmed. The Anthropic valuation history covers every round in detail.

Based on the latest disclosures, Anthropic's revenue has caught up with OpenAI's and likely passed it. Anthropic reported $16.3 billion in revenue for the first half of 2026 in its S-1, averaging about $2.7 billion a month. OpenAI said in March 2026 that it was generating $2 billion in revenue per month.

Anthropic's S-1 shows revenue grew from $1.163 billion in the first half of 2025 to $16.286 billion a year later, roughly 14 times higher. The company's own run-rate claims climbed from about $9 billion at the end of 2025 to above $30 billion by April 2026, according to its Amazon compute announcement. Bloomberg later reported that Anthropic told prospective investors its third-quarter revenue hit $16.8 billion with adjusted profitability, per Bloomberg Government. That figure comes from people familiar with the presentation, not a filing.

Read the loss line carefully. The S-1 reports an $80.7 billion GAAP net loss for the first half of 2026 alongside a positive $2.7 billion adjusted net income, so the gap comes from items the company excludes in its adjusted measure. Run-rate and recognized revenue also measure different things: run-rate annualizes a recent period, while recognized revenue counts what was booked. For OpenAI's side of the ledger, the OpenAI statistics page collects every revenue disclosure to date, and the Anthropic statistics page does the same for Claude's maker.

ChatGPT is the far larger consumer product, with more than 900 million weekly active users and over 50 million subscribers as of early 2026. Claude is smaller among consumers but anchors Anthropic's developer and enterprise business. Both companies shipped new flagship model families between September and October 2026.

OpenAI's release dates come from its developer changelog, and Anthropic's from the Claude Platform release notes. OpenAI reported more than 9 million paying business users of ChatGPT in its February 2026 update.

Anthropic's top tier works differently from OpenAI's. Claude Fable 5 launched June 9, 2026, as a "Mythos-class model that we've made safe for general use," while the less restricted Mythos 5 went only to cyberdefenders and vetted partners through Project Glasswing, per Anthropic's launch post. OpenAI has no equivalent gated tier in its public lineup.

On coding, the two are effectively a duopoly: Menlo Ventures estimates Claude Code and Codex together account for $24.0 billion of a $34.0 billion coding market, or 70%. For a hands-on comparison of the chat apps themselves, see the ChatGPT vs Claude breakdown.

At three of four tiers, OpenAI and Anthropic now charge identical list prices. GPT-6 Astra and Claude Fable 5.1 both cost $10 input and $50 output per million tokens. GPT-6.1 Sol matches Claude Sonnet 5.5 at $2 and $10, and GPT-6 Luna matches Claude Haiku 5.5 at $0.10 and $0.50, as of November 2026.

Prices are standard rates from OpenAI's API pricing page and Anthropic's Claude pricing page, both checked in November 2026. Both companies discount batch processing by 50%. Claude Haiku 5.5 rises to $0.50 input and $2.50 output when a prompt exceeds 100,000 tokens.

Since list prices match, the anthropic vs openai pricing question comes down to caching and token efficiency. Fable 5.1's cached input costs a quarter of Astra's, which favors workloads that reuse long prompts. Anthropic also says Opus 5.5 "costs 40% less to run than Opus 5" because it uses fewer tokens per task, a company claim on its Opus 5.5 page. The full rate cards live in the OpenAI API pricing guide, the Claude API pricing guide and the cross-vendor AI pricing index.

Anthropic leads on both enterprise measures published this fall. Menlo Ventures' November 2026 survey puts Anthropic at 55% of enterprise LLM API spend versus 31% for OpenAI. Ramp's card and bill-pay data shows 43.8% of US businesses paying for Anthropic in September 2026, compared with 40.6% for OpenAI.

The Menlo Ventures 2026 State of Enterprise AI report, fielded by Morning Consult, also found Google's share fell from 21% to 9%. The Ramp AI Index notes its figures likely undercount adoption because free tools and personal accounts are invisible to its data. Anthropic's S-1 adds more than 11,900 customers generating $100,000 or more in trailing revenue and about 250 above $10 million.

Both OpenAI and Anthropic gained share in Menlo's survey, which means the two are pulling away from every other lab rather than trading customers only with each other. For a wider view of anthropic competitors beyond OpenAI, the biggest AI companies ranking covers Google, SpaceXAI and others.

Both companies gate their most capable models behind published risk frameworks, but they apply them differently. Anthropic runs a Responsible Scaling Policy, now version 3.4, and restricts its least-guarded model to vetted partners. OpenAI uses a Preparedness Framework and ships models it classifies as High capability with added safeguards.

Anthropic's Responsible Scaling Policy version 3.4 took effect July 8, 2026. For Fable 5, classifiers route flagged cybersecurity, biology, chemistry and distillation requests to an older model, which Anthropic says happens in under 5% of sessions on average. OpenAI's October 2026 safety update says it is treating GPT-6 Sol and Luna as "High capability in both Cybersecurity and Biological and Chemical domains," with neither reaching its High threshold for AI self-improvement.

The practical gap shows up in access. Anthropic withholds a version of its top model from the public entirely, while OpenAI releases its top models broadly and leans on system-level safeguards. Safety also now shapes business timing: Altman cited safety concerns as the reason an OpenAI IPO would be "ill-advised" right now.

Both companies have spread compute across multiple partners, and they now share some of the same suppliers. Anthropic trains and serves Claude on AWS Trainium, Google TPUs, NVIDIA GPUs and AMD GPUs. OpenAI relies on Microsoft Azure, NVIDIA, Oracle's Stargate sites and, since 2026, Amazon, which committed $50 billion to OpenAI.

OpenAI also says it has already surpassed its goal of securing 10 GW of US AI infrastructure by 2029, according to its April 2026 infrastructure update.

Amazon now backs both companies, which blurs the old picture of Microsoft with OpenAI and Amazon with Anthropic. For investors following the listings, compute commitments are the biggest future cost line for both, and the Anthropic stock guide and OpenAI stock guide explain how to get exposure before and after each IPO.

Choose based on workload, not brand. Prices are identical at most tiers, so the deciding factors are product fit, caching patterns, cloud platform and model access. OpenAI suits teams that want the broadest consumer reach and a mid-priced Terra tier. Anthropic suits enterprise and coding workloads, plus heavy prompt caching.

The difference between OpenAI and Anthropic is smaller for buyers than for investors. With identical list prices at three tiers and both model families on Amazon Bedrock, the cost of testing one against the other on a real workload is low.

Anthropic is bigger by private valuation and enterprise API spend, but OpenAI is bigger by consumer reach. Anthropic's May 2026 Series H valued it at $965 billion, above OpenAI's $852 billion from March 2026, and Menlo Ventures puts Anthropic at 55% of enterprise LLM API spend. ChatGPT, however, has more than 900 million weekly users.

The biggest AI companies ranking compares both against the rest of the field.

No. Anthropic is an independent Delaware public benefit corporation founded in 2021, with no ownership tie to OpenAI. Its major outside backers include Amazon, which had invested $8 billion before committing up to $25 billion more in April 2026. Anthropic's Long-Term Benefit Trust elects a majority of its board through a special class of stock.

The Anthropic explainer covers its ownership and history in detail.

Anthropic filed a public S-1 on October 26, 2026, to list on the Nasdaq Global Select Market under the ticker ANT. The price range and share count had not been set at filing. Bloomberg reported that marketing to investors could begin as soon as the week of November 9, 2026, though the company has not confirmed a date.

Follow updates in the Anthropic IPO guide.

OpenAI is unlikely to go public in 2026. The company confirmed in June 2026 that it had submitted a confidential S-1 to the SEC, but CEO Sam Altman told Fortune in September 2026, "I would say not 2026," calling the current moment ill-advised because of AI safety concerns. No public filing or ticker has been announced.

The OpenAI IPO timeline tracks each development.

Neither is cheaper at most tiers, because list prices now match. As of November 2026, GPT-6 Astra and Claude Fable 5.1 both cost $10 input and $50 output per million tokens, and GPT-6 Luna and Claude Haiku 5.5 both cost $0.10 and $0.50. Claude is cheaper for cached prompts at the top tier.

The AI pricing index compares both against Google, SpaceXAI and others.

Anthropic is more popular with businesses by the latest data. Ramp's AI Index shows 43.8% of US businesses paying for Anthropic in September 2026, compared with 40.6% for OpenAI, based on card and bill-pay data from more than 85,000 companies. Menlo Ventures separately puts Anthropic ahead in enterprise LLM API spend, 55% to 31%.

Consumer usage is a different story, with ChatGPT far ahead.

The openai vs anthropic comparison has flipped on several key measures in 2026. As of November 2026, Anthropic holds the higher private valuation ($965 billion vs. $852 billion), leads enterprise LLM API spend 55% to 31% per Menlo Ventures, and has filed a public S-1 for a Nasdaq listing under ANT. Its filing shows $16.3 billion in first-half 2026 revenue. OpenAI remains the consumer leader, with more than 900 million weekly ChatGPT users and $2 billion in monthly revenue as of March 2026, and it has delayed any IPO past 2026. API list prices are now identical at three tiers, so buyers should choose on workload fit, caching and cloud platform rather than headline price.

Written by the AI Business Weekly Editorial Team. Reviewed, edited and published by Sameer Khan. This article was AI-assisted, then reviewed by Sameer Khan before publishing.