OpenAI is bigger. Anthropic is earning more. Both companies have filed to go public, and that gap is about to get a lot of attention.
The basic IPO story is well known by now. OpenAI confidentially filed last week, a few days after Anthropic did the same. Both are racing to Wall Street while public investors still have an appetite for AI risk. The part that's gotten less attention is the revenue gap underneath all of it.
Anthropic's annualized run rate hit about $30 billion in April, according to reporting compiled by The AI Corner. OpenAI was at roughly $24 billion at the same point. By late May, Anthropic's number climbed to around $47 billion. Fifteen months earlier, it had been at $1 billion.
OpenAI has more users. Anthropic has the kind of business that bankers actually want to talk about:
- About 80% of Anthropic's revenue comes from business customers. OpenAI's mix still leans heavily on consumer subscriptions.
- More than 1,000 business customers now spend over $1 million a year with Anthropic. That number doubled in less than two months.
- Among companies buying AI tools for the first time in 2026, Anthropic is capturing roughly 73% of the spend. OpenAI's share of that cohort dropped to 27%.
- Per dollar of capital raised, Anthropic generates about $0.23 in ARR. OpenAI generates about $0.11.
A lot of that traces back to a bet Anthropic made early. The company positioned itself as the AI you trust with the work that actually matters, leaning hard on safety, reliability, and fewer hallucinations. For a while the pitch sounded like marketing. Now it's showing up in procurement decisions.
A CIO at a top-20 US financial institution recently explained why his team picked Claude over GPT for contract review. His legal team ran a six-week side-by-side evaluation, and Claude hallucinated at roughly a third the rate of GPT-4o. "For a company our size, that's not a feature preference," he said. "That's a risk reduction."
That's the wedge Anthropic has been driving into. Sequoia principal Lina Sandoval told reporters that Anthropic "successfully converted their safety narrative into an enterprise sales asset," and the open question is whether they can hold that position as competitive pressure builds. Dario Amodei has been making the same point in plainer language at enterprise events, framing Anthropic as the AI that the world's most consequential organizations rely on when the stakes are genuinely high. That positioning maps unusually well onto how Fortune 500 budgets actually flow.
The timing matters too. SpaceX is reportedly close to its own IPO, and public markets only have so much capital they'll commit to a single risky category at once. Patrick Healy, who runs IPO advisory firm Issuer Network, told the Wall Street Journal that SpaceX will absorb an enormous amount of that capital, and whoever goes second will be in a much better spot than whoever goes third. Gil Luria at D.A. Davidson said it more bluntly: what OpenAI does not want is for the public market to run dry before its turn.
When OpenAI's S-1 eventually lands, the story Wall Street reads will be a side-by-side. OpenAI still loses money at an extraordinary clip. Anthropic's losses are smaller, its enterprise base is stickier, and its capital efficiency is roughly twice as good. None of that guarantees Anthropic wins long term. OpenAI's whole bet is that its training spend produces step-change models that unlock new revenue lines the efficiency math can't predict. Some analysts also argue Anthropic's run-rate deserves more scrutiny in an S-1, since there's an ongoing debate about whether the number is gross or should be restated net of what gets paid out to compute partners.
For three years the AI story has been told in benchmark scores and release notes. The IPO process is about to force a different conversation, one about who actually makes money and how. OpenAI built the brand. Anthropic built the business. If the public market decides it values one of those things more than the other, the pecking order in AI is going to look very different by the end of the year.
