SemiAnalysis says it detected Anthropic A/B testing Claude Max limits, with a 19% larger five hour window but a 20% smaller weekly budget on one account; Anthropic has not confirmed
馃毃馃毃ALERT: ANTHROPIC IS A/B TESTING USAGE LIMITS Many users on X are reporting LOWER usage limits right now. THEY ARE NOT WRONG. We detected an A/B test going on that DECREASES your monthly API-value by ~20% while INCREASING your 5h usage limits by ~20%. This only affects SOME accounts. (1/2)馃У
Context
Heavy Claude Max users could get less usage over a month under the pattern described, but the claim rests on two accounts measured by a research firm, not on any statement from Anthropic.
SemiAnalysis is a semiconductor and AI research firm, and its post is a third party claim about Anthropic, not an Anthropic announcement. Anthropic's Max plan help page describes five hour and weekly usage limits and says Anthropic may apply other limits at its discretion. The post is marked as part one of two, and the second post was not retrieved for this entry. No Anthropic statement confirming or denying a test was found as of this scan.
Deep dive
SemiAnalysis posted at 5:36 PM Eastern on October 22 that it detected an A/B test that lowers monthly API value by about 20% while raising five hour limits by about 20%, affecting only some accounts. It says many users on X had been reporting lower limits.
The attached chart is sourced to the SemiAnalysis Tokenomics Model. It compares two Max 20x accounts, using the same model, Opus 5.5, measured on the same day. In its figures, Account A has a five hour window of 1,740 and Account B has 2,076, a difference of 19%, measured in millions of agentic tokens. The weekly budgets are 6,579 for Account A and 5,266 for Account B, which is 20% lower. The chart converts these into a monthly API equivalent value of $11,726 for Account A and $9,385 for Account B.
Those numbers are SemiAnalysis's own measurements from two accounts, so the sample is small.
SemiAnalysis's October 5 newsletter, which is marked as paid, describes its general method of measuring how far each provider's usage meter moves per token type. In that piece it also says one unnamed provider confirmed an extremely tiny A/B test on limits; the article does not name the provider, and it predates this post.
Anthropic's Max plan help page confirms that plans have session limits that reset every five hours and weekly limits, and that Anthropic may limit usage in other ways. No Anthropic statement addressing the SemiAnalysis claim was found.
What to expect next
Anthropic has not publicly confirmed or denied a test of this kind in the sources reviewed, so the open questions are whether it responds and whether other accounts show the same split. SemiAnalysis marked its post as part one of two. Because the measurement covers two accounts, whether it applies to other Max tiers or to most accounts is not established. Anthropic's help page says users can see their next reset time under the Usage page in Claude settings.