Anthropic vs OpenAI: Founders, CEOs and History
Anthropic was founded in 2021 by Dario Amodei, Daniela Amodei, Jack Clark and is led by Dario Amodei. OpenAI was founded in 2015 by Sam Altman, Elon Musk, Greg Brockman and is led by Sam Altman.
Company facts
Founders
Anthropic
Dario Amodei
Dario Amodei is co-founder and Chief Executive Officer of Anthropic PBC. He previously served as Vice President of Research at OpenAI, directing the teams that built GPT-2 and GPT-3 and the scaling law research that still shapes how frontier models are planned…
Daniela Amodei
Daniela Amodei is co-founder and President of Anthropic PBC, responsible for the commercial and operating side of the company: go-to-market, finance, people, investor relations and public benefit compliance.
Jack Clark
Jack Clark is a co-founder of Anthropic and its head of policy. Since March 2026 he has also led the Anthropic Institute, a think tank the company launched to study the effects of AI.
Sam McCandlish
Sam McCandlish is a co-founder of Anthropic and a researcher known for work on the scaling laws of neural networks. At OpenAI he co-authored research showing a predictable relationship between training compute and model performance.
Jared Kaplan
Jared Kaplan is a co-founder and Chief Science Officer of Anthropic. He was a lead author of 'Scaling Laws for Neural Language Models' in 2020, which showed that model loss falls predictably as compute, data and parameter count increase.
Tom Brown
Tom Brown is a co-founder of Anthropic and was the lead author of the 2020 GPT-3 paper 'Language Models are Few-Shot Learners' at OpenAI, which showed that large language models can handle many tasks from a few examples without task-specific fine-tuning.
Chris Olah
Chris Olah is a co-founder of Anthropic and leads its interpretability research, which works out which internal features and circuits drive a model's behaviour.
Ben Mann
Ben Mann is a co-founder of Anthropic and one of the authors of OpenAI's 2020 GPT-3 paper 'Language Models are Few-Shot Learners'. At Anthropic he has worked on training and aligning the Claude models and on the practices that govern how they are released.
OpenAI
Sam Altman
Sam Altman co-chaired OpenAI at its 2015 founding and became CEO in 2019. He negotiated the Microsoft partnership, oversaw the ChatGPT launch in 2022, survived the board's brief attempt to remove him in November 2023, and led the October 2025 recapitalization…
Elon Musk
Elon Musk was an early co-chair and funder of OpenAI and left its board in February 2018. He later founded rival xAI in 2023 and sued OpenAI, Sam Altman and Greg Brockman in 2024, arguing the company abandoned its nonprofit mission.
Greg Brockman
Greg Brockman left his role as Stripe CTO to co-found OpenAI in 2015 and serves as president.
Ilya Sutskever
Ilya Sutskever was OpenAI's chief scientist from 2015 to May 2024, overseeing work behind the GPT series and ChatGPT. He voted to remove Sam Altman in November 2023, then said he regretted it. After leaving OpenAI he co-founded Safe Superintelligence Inc.
CEOs and their tenures
Anthropic
- Dario Amodei2021–present
Chief Executive Officer and Co-Founder
Co-founded Anthropic in January 2021 and has run it since. Revenue reached $4.59 billion in 2025 and an annualized run-rate of about $65 billion by July 2026, and the company was valued at $965 billion post-money in its May 2026 Series H.
Source
OpenAI
- Greg Brockman2015–present
President and Co-founder
Former Stripe CTO; returned from a 2024 sabbatical and remains president.
Source - Mira Murati2018–2024
Chief Technology Officer and interim CEO (former)
Served as interim CEO for two days in November 2023; left OpenAI in 2024.
Source - Sam Altman2019–present
Chief Executive Officer
Co-founder and CEO who turned OpenAI from a research lab into a consumer and enterprise platform; briefly removed by the board in November 2023 and reinstated days later.
Source - Fidji Simo2025–2026
CEO of Applications (former)
Former Instacart CEO who ran ChatGPT and other applications; stepped down from the full-time role in July 2026 for health reasons and stayed on as an adviser.
Source - Vijaye Raji2025–present
CTO of Applications
Statsig founder who joined via the 2025 acquisition to head product engineering for ChatGPT and Codex.
Source
Timeline: Anthropic and OpenAI side by side
2015OpenAI
OpenAI founded as a nonprofit
OpenAI launched in December 2015 as a nonprofit AI research lab.
2019OpenAI
Capped-profit entity and Microsoft deal
OpenAI created a capped-profit subsidiary and received a $1 billion investment from Microsoft.
2021Anthropic
Anthropic founded by former OpenAI staff
Dario Amodei, Daniela Amodei and five other former OpenAI employees incorporated Anthropic on January 26, 2021, and raised a $124 million Series A in May 2021 led by Jaan Tallinn.
2022Anthropic
$580 million round and the first Claude held back
Anthropic raised $580 million in April 2022, including $500 million from FTX. It finished training the first version of Claude that summer but did not release it, citing further safety testing.
2022Anthropic
Constitutional AI published
Anthropic published Constitutional AI, a training method in which the model critiques and revises its own answers against a written set of principles instead of relying only on human ratings.
2022OpenAI
ChatGPT launch
ChatGPT launched on November 30, 2022 and reached 100 million users faster than any prior consumer app.
2023Anthropic
Claude and Claude 2 released
Claude and Claude Instant were released in March 2023 to approved users, and Claude 2 opened to the public in July 2023.
2023Anthropic
Amazon and Google take stakes
Amazon announced a strategic collaboration in September 2023 with an initial $1.25 billion investment and AWS as primary cloud provider. Google invested $500 million in October 2023 and committed $1.5 billion more over time.
2023OpenAI
Board crisis
The nonprofit board removed Sam Altman in November 2023; he returned as CEO within days and the board was rebuilt.
2024Anthropic
Claude 3 family and Claude 3.5 Sonnet
Anthropic released Claude 3 Opus, Sonnet and Haiku on March 4, 2024, then Claude 3.5 Sonnet in June 2024, which became the default model inside many AI coding tools.
2024Anthropic
Amazon investment reaches $8 billion
Amazon invested a further $4 billion in November 2024, taking its total to $8 billion. Anthropic named AWS its primary training partner and agreed to train on AWS Trainium chips.
2025Anthropic
Claude 4 and Claude Code general availability
Anthropic released Claude Opus 4 and Claude Sonnet 4 in May 2025 at its first developer conference, and made the Claude Code command line agent generally available the same month.
2025Anthropic
$1.5 billion copyright settlement with authors
Anthropic agreed in September 2025 to pay $1.5 billion, about $3,000 per book, to settle the Bartz class action over pirated books used in training. A judge granted final approval on July 20, 2026.
2025Anthropic
Google TPU deal for up to one million chips
In October 2025 Anthropic agreed to expand its use of Google Cloud to as many as one million TPUs, adding well over a gigawatt of capacity in 2026.
2025Anthropic
Microsoft and NVIDIA commit up to $15 billion
In November 2025 NVIDIA committed up to $10 billion and Microsoft up to $5 billion, while Anthropic agreed to buy about $30 billion of Azure compute and put Claude on Azure Foundry.
2025Anthropic
Bun acquired as Claude Code passes $1 billion run-rate
Anthropic acquired Bun, the JavaScript and TypeScript runtime behind Claude Code and the Claude Agent SDK, in December 2025, and said Claude Code had reached $1 billion of run-rate revenue.
2025OpenAI
Acquired Jony Ive's io
OpenAI agreed to buy hardware startup io for just under $6.5 billion in an all-equity deal.
2025OpenAI
Recapitalization into OpenAI Group PBC
In October 2025 the for-profit became a public benefit corporation controlled by the OpenAI Foundation; Microsoft received about 27%.
2026Anthropic
Series G of $30 billion at a $380 billion valuation
Anthropic raised $30 billion in February 2026 led by GIC and Coatue at a $380 billion post-money valuation, and reported run-rate revenue of $14 billion and more than 500 customers spending over $1 million a year.
2026Anthropic
Pentagon dispute over surveillance and weapons limits
Anthropic refused Department of Defense demands in February 2026 to drop restrictions on mass domestic surveillance and fully autonomous weapons.
2026Anthropic
Series H of $65 billion at a $965 billion valuation
Anthropic raised $65 billion in May 2026 led by Altimeter, Dragoneer, Greenoaks and Sequoia at a $965 billion post-money valuation, and said run-rate revenue had crossed $47 billion that month.
2026Anthropic
Confidential draft S-1 submitted to the SEC
On June 1, 2026 Anthropic confidentially submitted a draft registration statement on Form S-1 for a proposed initial public offering of common stock.
2026Anthropic
Claude Opus 5 and Opus 5.5 released
Claude Opus 5 replaced Opus 4.8 as the flagship in July 2026, and Opus 5.5 followed on September 22, 2026 at $4 per million input tokens and $20 per million output tokens, about 40 percent cheaper to run than Opus 5.
2026Anthropic
IPO prospectus figures reported
Reporting on the draft prospectus in late September 2026 disclosed 2025 revenue of $4.59 billion, an $8.06 billion operating loss, a $41.97 billion net loss and about $518 billion of long-term compute commitments.
2026OpenAI
$122B funding round
OpenAI closed $122 billion in committed capital at an $852 billion post-money valuation on March 31, 2026.
2026OpenAI
Run rate nears $70B
Axios reported in September 2026 that annual recurring revenue was nearing $70 billion.
Acquisitions
Anthropic
- Vercept2026Undisclosed
- Stainless2026Undisclosed
- Mendral2026Undisclosed
- Humanloop2025Undisclosed
- Bun2025Undisclosed
OpenAI
- io Products2025$6.5B
- Statsig2025$1.1B
- Rockset2024Undisclosed
- Global Illumination2023Undisclosed
Questions about Anthropic vs OpenAI
Who is the CEO of Anthropic PBC and OpenAI?
Anthropic PBC is led by Dario Amodei and OpenAI is led by Sam Altman. Both serve as the top executive responsible for the company's strategy, operations, and financial performance.
When was Anthropic PBC founded vs OpenAI?
OpenAI was founded in 2015 — 6 years before Anthropic PBC, which was founded in 2021. OpenAI's longer operating history gives it a deeper track record but also potentially more institutional inertia compared to the younger Anthropic PBC.
How many employees does Anthropic PBC have compared to OpenAI?
Anthropic PBC employs approximately 2,500 people, while OpenAI employs approximately 4,500. OpenAI has the larger workforce at 4,500 employees, compared to Anthropic PBC's 2,500. A higher headcount does not necessarily imply greater efficiency — it often reflects differences in business model (e.g., manufacturing vs. software).
Where are Anthropic PBC and OpenAI headquartered?
Both Anthropic PBC and OpenAI are headquartered in United States, meaning they operate under the same primary regulatory and tax environment.
Who founded Anthropic PBC and OpenAI?
Anthropic PBC was founded by Dario Amodei, Daniela Amodei, Jack Clark, Sam McCandlish, Jared Kaplan, Tom Brown, Chris Olah, Ben Mann. OpenAI was founded by Sam Altman, Elon Musk, Greg Brockman, Ilya Sutskever.
Which company has a longer operating history — Anthropic PBC or OpenAI?
OpenAI has been operating for approximately 11 years, making it the more established of the two companies. Anthropic PBC has been in operation for around 5 years. A longer operating history often signals greater institutional resilience and brand recognition, though it can also mean slower adaptation to new market conditions.
Figures come from each company's filings and the sources linked beside them. Amounts reported in another currency are shown in US dollars at an approximate rate and marked with ~. Back to the Anthropic vs OpenAI overview