Anthropic passed OpenAI in revenue. Read how it's counted.

Did Anthropic pass OpenAI in revenue? On the scoreboard the tech press ran, yes. Anthropic reported a run-rate of $47 billion in May 2026, against OpenAI's roughly $24 billion. The headline wrote itself, and it was a good one: the younger company overtook the leader and posted the fastest revenue growth anyone has clocked in software.

Then read how each number is built. Anthropic counts revenue gross. When a business runs Claude through Amazon, Google, or Microsoft's cloud, Anthropic books the whole bill the customer pays and lists the cloud provider's share as an expense. OpenAI reports closer to net, roughly what lands in its own account. The leaderboard sets a top line that includes partners' money next to one that mostly does not. When OpenAI disputed the figure in May 2026, it netted Anthropic down to about $22 billion, a shade under OpenAI's own run-rate. Same week, two companies, and the gap depends on who is counting.

The point is narrow and it matters. Anthropic's growth is real, and its business is arguably healthier than OpenAI's. Saying it "passed OpenAI in revenue" still compares two different measurements, and the cleaner the comparison gets, the smaller the lead. In October, an IPO will force the first audited number, and the gross-to-net question stops being a debate.

What "gross" actually adds

Anthropic sells Claude two ways: direct through its own API, and through the big cloud marketplaces. Amazon Bedrock, Google Vertex, and Microsoft Azure resell Claude to their enterprise customers and keep a cut of every dollar. Anthropic books the full customer spend as revenue, then records the resellers' share as a cost. Reporting on its IPO preparations put this practice at the center of the revenue question.

The accounting is defensible, and it is common for a company that owns the product being resold. It also lifts the top line against a rival that reports net. OpenAI sells mostly direct, through ChatGPT subscriptions and its own API, so its reported revenue sits closer to the cash it keeps. Line the two up and the gross reporter looks bigger for reasons that have little to do with how much either company earns. The leaderboard that ranked them admitted as much: the top two "aren't perfectly apples-to-apples."

The netted numbers run close

When Anthropic's run-rate hit $30 billion in April, OpenAI argued that stripping out the cloud partners' share brought the real figure near $22 billion. OpenAI's own run-rate then sat around $24 billion, about $2 billion a month. On a like-for-like net basis the two were within touching distance, and OpenAI was arguably still in front.

Independent trackers land in the same place on timing without picking a method. Epoch AI, which builds estimates from The Information, Bloomberg, Reuters, and company disclosures, projected the crossover for around August 2026 at roughly $43 billion in annualized revenue, with a wide band running from early 2026 into 2027. The crossover is real on the trend. Where it lands to the dollar depends on definitions nobody has standardized.

A run-rate is a projection, not a year

Run-rate revenue is last month's figure multiplied by twelve. It is a snapshot annualized, and for a company doubling every few months it flatters. Anthropic's own fundraise announcements tracked the climb: $9 billion at the end of 2025, $14 billion in February 2026, $30 billion in April, $47 billion by late May. Fast, and still a forward projection rather than money in the bank.

Booked revenue moves slower. OpenAI exited 2025 near $20 billion in annualized revenue yet recorded well below that across the full year, because it spent most of the year under the exit rate. The same gap applies to Anthropic. A $47 billion run-rate in May does not mean $47 billion collected in 2026. It means May, times twelve, if May holds. For anyone weighing what the AI boom is worth, the run-rate is the marketing number and the audited year is the one to wait for.

Why the mix still favors Anthropic

Here is the part the accounting critique does not erase. The two sell to different customers, and Anthropic's pay better. About 85% of Anthropic's revenue comes from enterprise and developer accounts. About 85% of OpenAI's comes from ChatGPT subscriptions, and roughly 95% of those users pay nothing. Enterprise usage is heavier, steadier, and priced higher per token, which is why Anthropic reported an operating profit while OpenAI projects a $14 billion loss for 2026 and no profit before the end of the decade.

So the honest read cuts both ways. The leaderboard oversells Anthropic's lead by mixing gross and net. The underlying business quality understates it, because enterprise revenue is worth more per dollar than free consumer signups that cost money to serve. It is the same split we traced when OpenAI cut its consumer prices: the consumer side buys reach, the enterprise side pays the bills. It also fits how little these platforms reveal about their own economics, the theme when AI marketplaces stayed quiet about their take rates.

What the IPO settles

Anthropic filed confidentially for an IPO on June 1, 2026, with Goldman Sachs, JPMorgan, and Morgan Stanley leading, aiming at a Nasdaq listing around October and an offering that could raise more than $60 billion. At its $965 billion private valuation on roughly $30 billion in revenue, the stock would price near 32 times sales, a multiple that only holds if the revenue is what it looks like.

An S-1 changes the terms because it is audited. Public filings report revenue net under standard accounting, and they split booked results from run-rate projections. When the prospectus lands, the market will see for the first time how much of the $47 billion headline survives the move from gross to net, and from run-rate to a real year. That figure, not the fundraise press releases, sets the price. Watch for it in the fall.

Sources

• Simon Willison, "Anthropic's run-rate revenue hits $47 billion," May 29, 2026
• Epoch AI, "Anthropic could surpass OpenAI in annualized revenue by mid-2026"
• Forbes, Paulo Carvao, "OpenAI And Anthropic Are Testing Two Very Different AI Business Models," May 21, 2026
• TechTimes, "Anthropic IPO Picks Goldman Sachs, Morgan Stanley, JPMorgan: Revenue Accounting Question Looms," June 5, 2026
• aibusiness.vc, "AI Revenue Leaderboard 2026"
• CNBC, "Anthropic tops OpenAI as most valuable AI startup, nears $1 trillion valuation," May 28, 2026

This is not financial advice.