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Initial research 2026-09-21Anthropic

Claude Sonnet 5.5

Provider status: active · Identity verified 2026-10-08 · Official catalog

Inspect the documented capabilities, access conditions and sources for your task.

Initial research: 2026-09-21. Check current terms before choosing.

Automated fact checks · 8 fields

AI extraction with a second evidence validation pass. These dates apply to the listed fields.

  • Input token price · 2026-10-08 · Source
  • Output token price · 2026-10-08 · Source
  • API access · 2026-10-08 · Source
  • identity · 2026-10-08 · Source
  • Work with long documents · 2026-10-06 · Source
  • Use extended reasoning · 2026-10-06 · Source
  • Understand images · 2026-10-06 · Source
  • Call tools and functions · 2026-10-06 · Source

Updated

The facts

Version
5.5
Price
$2 input / $10 output per million tokens. API usage. Tokens are pieces of text sent to or generated by the model. This is not a chat subscription.
API
✓Supported
Open weights
?Not verified
Commercial use
unknown
Long context
✓Supported

1M token context window

Source for Long context (opens in a new tab)
Tool use
✓Supported

Tool use supported; forced tool use and between_tools thinking control documented

Source for Tool use (opens in a new tab)
Vision input
✓Supported

Input supports text and images

Source for Vision input (opens in a new tab)
Extended thinking
✓Supported

Adaptive thinking on by default, default effort high

Source for Extended thinking (opens in a new tab)

From the publisher

Automatic source checks. These do not change the verification date of the facts above.

Sources

Beyond feature support

Quality evidence.

How well a model performs depends on the task, version, and settings.

We have not published a reviewed quality evaluation for these versions yet. Feature support and price do not establish output quality.

Try the same small task with each option. Check accuracy, consistency, and how much editing you need to get a usable result.

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