On September 1 (local time), Anthropic announced that it has reset the 5-hour and 1-week usage limits for its AI service, Claude. This measure was taken in conjunction with the release of the new AI model, Claude Fable 5.1, announced on the same day.
Model ReleasesPricing & LimitsAnthropicClaude Fable 5.1
Anthropic Releases Claude Fable 5.1 and Resets Usage Limits
This article is a translation. Read the Japanese original
Compared to its predecessor, Claude Fable 5, Claude Fable 5.1 shows improved performance in autonomously handling tasks in fields such as scientific research and coding.
In terms of cost, cache read fees have been reduced by 75%. Regarding token-based billing for APIs and other services, the company stated that it has achieved cost reductions of approximately 25% for general tasks and up to approximately 45% for complex coding tasks.
Additionally, the company announced "Claude Mythos 5.1," which features a modified safety level. This model is provided exclusively to the company's certified partners, with the aim of supporting the cybersecurity and life sciences sectors.
--- Source: “Claude” usage limits “batch reset” following the release of “Fable 5.1” (ITmedia AI+, 2026-09-02)