Language Models
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The current Claude lineup: 1M context, 128K output, retirement more than a year out

2026/09/02

The current lineup is four models: Fable 5.1, Opus 5, Sonnet 5 and Haiku 4.5⁠[1].

Context is 1 million tokens on Fable 5.1, Opus 5 and Sonnet 5, and 200K on Haiku 4.5⁠[1]. Maximum output in one synchronous response is 128K tokens on the first three and 64K on Haiku 4.5⁠[1]. On the batch API, Opus 5 and Sonnet 5 reach 300K behind a beta header, and Fable 5.1 is not on that list⁠[1].

Reliable knowledge cutoffs are June 2026 for Fable 5.1, May 2026 for Opus 5, January 2026 for Sonnet 5, and February 2025 for Haiku 4.5⁠[1].

Retirement dates are published as commitments not to retire sooner than a given day: 15 October 2026 for Haiku 4.5, 30 June 2027 for Sonnet 5, 24 July 2027 for Opus 5, and 1 September 2027 for Fable 5.1⁠[1]. Those cover the platforms Anthropic operates⁠[1]. Amazon Bedrock and Google Cloud set their own⁠[1].

One million tokens is roughly 555k words on the current tokenizer⁠[1]. On models before Claude Opus 4.7 the same million tokens held about 750k words, so across generations the window grew less than the number suggests⁠[1].