Anthropic and OpenAI's revenue chasm, explained

Anthropic and OpenAI's revenue chasm, explained

Madison Mills

Thu, September 3, 2026 at 12:00 PM GMT+3 3 min read

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Anthropic is racing toward an IPO with a headline revenue number that will likely look bigger than that of its rival, OpenAI.

Why it matters: Comparing revenue at the two AI labs isn't apples-to-apples unless you understand how differently they account for some sales through cloud partners.

Driving the news: The latest update from Anthropic indicates its annualized revenue will exceed $65 billion this year. OpenAI says it's on track to exceed $40 billion in annualized revenue.

• Both companies annualize recent sales in roughly similar ways, The Information reported.

• The biggest difference is what goes into that number.

Between the lines: Anthropic records the full value of Claude sales through its partners, then records the cloud providers' cuts as expenses.

• OpenAI records only its share of certain sales through partners like Microsoft, according to The Information.

• If a customer pays $100 for an AI service through a cloud provider, Anthropic's accounting method allows it to record the full $100 as top-line revenue, per Francine McKenna, accounting professor and author of the newsletter The Dig. The cloud provider's cut is then listed an expense.

Zoom in: Why do both AI labs do it differently?

• "The criteria here has a lot to do with who is the principal and who is the agent in the transaction," McKenna says. It's about who really has control over the client relationship and is ultimately responsible for delivering the product, McKenna adds.

• Anthropic views itself as the principal in each transaction, which allows it to report gross revenue.

• OpenAI sees net revenue as more accurate.

What they're saying: Neither approach is necessarily wrong.

• "You can have two companies with the same business model come to a different conclusion," McKenna says, based on both customer contracts and what argument their teams made to the SEC to justify their revenue calculations.

• Accounting is "more of an art than a science," Lucas Ward, co-founder and CEO of Oath, a financial verification platform, told Axios.

Reality check: Accounting can't explain the entire $25 billion Anthropic-OpenAI gap based on what we know publicly.

• If Anthropic were to pivot and report revenue on a net versus gross basis, that would only amount to about a 6%–10% hit, per a source familiar with the company's financials.

• That would still put Anthropic roughly $19 billion to $21 billion ahead of OpenAI, based on the latest reported figures.

What we're watching: Anthropic's IPO filing should finally show investors how it justifies its revenue treatment.

• As part of the pre-IPO paperwork process, correspondence between the SEC and Anthropic will get released. That should include justifications for Anthropic's accounting practices.

• Ward plans to watch Anthropic's EBITDA, or earnings before interest, taxes, depreciation and amortization, for clarity on the firm's true profits.

The bottom line: Anthropic may really be growing faster than OpenAI.

• But $65 billion vs. $40 billion isn't a clean comparison between the two.

Lucinda Shen contributed reporting on this story.

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