Will Anthropic be the second-best Code Arena | WebDev AI lab at the end of September 2026?

Analysis

The most concrete fact in the record is this: as of the most recent official snapshot taken around September 23 and 24, Anthropic's Claude sits at Lab Rank number one on the Code Arena WebDev leaderboard, not number two. That single data point complicates any claim that Anthropic will occupy the runner-up spot when the market checks the table on September 30. The picture is not static, though. Reporting from earlier in September described a different order entirely, with OpenAI's model leading and Anthropic's Claude Fable model in second place behind it. That earlier snapshot even noted the top two were separated by a relatively narrow margin, showing how quickly these rankings can shuffle as labs push out new model versions. This volatility is the core reason the forecast leans against Anthropic settling into second. Having occupied first place in the most recent read, Anthropic would need to slip back down exactly one rung, and stay there, by the deadline. That is plausible given how often these leaderboards have reordered themselves in recent weeks, but it is not the default trajectory suggested by the latest checkpoint. The single thing to watch is whichever new model release or leaderboard update lands closest to September 30, since even one fresh entrant near the top has already been enough to reshuffle first and second place before.