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Sweep 22 Oct 2026 · 04:32Z Build v2.1.308 527 read Stable v2.1.308 Latest v2.1.308 Next v2.1.308 Feeds RSS JSON llms.txt llms-full.txt Unofficial
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Claude Code v2.1.247 ·

Sonnet 5 default context window raised to 1,000,000 tokens

Sonnet 5's default context window is now a full million tokens, up from 967,000.

You'll notice Notable Improvements
JSON All of v2.1.247
You'll noticeTier: how much it should matter to you
5Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
ModelsArea: what it touches
ImprovementsKind: in v2.1.247,
What probably matters to youSection of the release
What

The built-in context size for claude-sonnet-5 went from 967,000 to 1,000,000 tokens. The smaller 500,000 limits used for remote cowork and local agent runs are unchanged.

Evidence

"claude-sonnet-5"

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Read from
Names in the bundleclaude-sonnet-5
Since it was published

The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.

Added since A small documentation edit on Models overview touched a line naming claude-sonnet-5 after this was published. | [Claude Platform on AWS ID](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws) | `claude-fable-5-1` | `claude-opus-5` | `claude-sonnet-5` | `claude-haiku-4-5` | models/overview see the edit
Confirmed since Anthropic's documentation has since written up claude-sonnet-5, on Create Session. - `BetaManagedAgentsModel = "claude-fable-5-1" or "claude-sonnet-5" or "claude-fable-5" or 11 more or string` api/beta/sessions/create see the edit
How sure we are
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agreesAnthropic's documentation has since written up claude-sonnet-5, on Create Session.

See this entry in the whole of v2.1.247 →

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