Replit makes OpenAI its default model partner as Anthropic slips to optional

Replit, the browser-based coding platform popular with founders and developers, is no longer working with Anthropic, co-founder and CEO Amjad Masad said on stage at TechCrunch Disrupt.

Masad attributed the decision to a mix of cost, partnership and performance. "I think ChatGPT is better now," he said, adding that Replit runs internal benchmarks alongside a public one and that OpenAI's models consistently perform better at building vibe-coded applications from scratch.

Replit announced a partnership with OpenAI in August, but had given no indication that it was ending its Anthropic relationship. Before that deal, Replit relied on Claude models to run its platform — a partnership credited with helping revenue grow — and Masad said the company had until recently been a top-five Anthropic customer.

After the panel, Masad clarified that Anthropic has not been cut out entirely: customers can still access Claude models on the platform, but ChatGPT is now the default. The shift could materially reduce Replit's Anthropic spend, since most customers stick with the default rather than choosing a model themselves.

"Replit remains model agnostic," Masad told TechCrunch over the weekend. "Our users can choose Anthropic's Claude or other supported models... OpenAI is now our preferred partner for powering Replit Agent, based on performance, economics, and the strength of our partnership."

His account was disputed by people familiar with the Anthropic relationship, one of whom said the partnership was still in place. Replit's own site, blog and social posts complicate the picture: a late-September blog post cited Claude Fable 5 and Fable 5.1 running in Replit Agent's production environment.

On stage, Masad also described how the revenue mix is shifting. Enterprise was about 2% of revenue last year and roughly 15% this year, with more than half of revenue now B2B; he expects enterprise and government customers to contribute more than half in 2027.

For model vendors, the episode is a reminder that defaults inside developer tools can matter more than leaderboard position when it comes to actual API traffic. What to watch next is whether Replit's public benchmark and billing structure change accordingly, and whether Anthropic loses a high-value channel or keeps it through direct customer choice.