❯ SemiAnalysis testing: at the same subscription price, Claude Opus 5.5 offers about five times the usage of GPT-6.1 Sol

What $20 buysResearch firm SemiAnalysis limit-tested AI subscription plans from nine companies and concluded that at the same price, Anthropic subscriptions provide about 5x the usage of OpenAI’s when converted at API list prices. A $20 Claude Pro plan on Opus 5.5 is worth about $1,200 of API usage, against about $280 for a $20 ChatGPT Plus plan on GPT-6.1 Sol. At the $200 tier the figures are about $12,000 and $1,400.

How it was measuredSubscription plans do not publish exact allowances and show only a usage meter. According to Implicator, SemiAnalysis fed chunks of War and Peace and technical essays into paid accounts, recorded how many tokens each tick of the meter consumed, and converted the totals into dollars using each lab’s public API prices and its own September mix for agent workloads, to within plus or minus 5%.

OpenAI just halved its limitsThe gap widened with recent changes. OpenAI halved the allowances for every model tier in its $200 plan, with existing subscribers keeping old limits until October 29. Its new $500 plan offers only 21% more Astra usage than the old $200 plan. Anthropic raised Opus allowances while cutting Opus 5.5 pricing. Limits on the two flagships, Fable 5.1 and GPT-6 Astra, are similar, and the fivefold gap is in the mid-tier models.

Generous limits mean thin marginsThe report cautions that the figure measures allowances at list prices and does not prove a subscriber finishes five times as many tasks. It also estimates that if users consumed their full Opus 5.5 allowance, Anthropic’s gross margin would be minus 369%, turning positive at 6% only at an average 20% consumption. Subscriptions are about a tenth of Anthropic’s revenue but consume more than 40% of its inference compute.

▮ SIGNALSubscriptions all cost $20 and $200, so the real price war is fought over allowances nobody can see, and whoever gives more is trading gross margin for users.