Anthropic releases Claude Sonnet 5.5, which it says is faster than Sonnet 5

Anthropic says Sonnet 5.5 generates outputs 30 percent or more faster than Sonnet 5, at $2 per million input tokens and $10 per million output tokens.

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Check our sources · 6 facts from 1 source

The API name is claude-sonnet-5-5. Anthropic says Sonnet 5.5 generates outputs 30 percent or more faster than Sonnet 5 and, in its own testing, costs up to 30 percent less per task. It reports 70.6 percent on Terminal-Bench 4.0, against 10.3 percent for Sonnet 5. These are figures from Anthropic itself.

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1 Claude Sonnet 5.5Anthropic · 28 Sep 2026 · 6 facts

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Claude Sonnet 5.5 costs $2 per million input tokens and $10 per million output tokens. Quote: "$2 per million input tokens, $10 per million output tokens"

Sonnet 5.5 is priced the same as Sonnet 5 at $2 per million input tokens, $10 per million output tokens, and $0.20 per million tokens for cache reads
The API model name is claude-sonnet-5-5. Quote: "claude-sonnet-5-5"

Developers can get started on the Claude Platform with claude-sonnet-5-5.
Anthropic says Sonnet 5.5 is available on all platforms, including Amazon Web Services, Google Cloud and Microsoft Azure. Quote: "Claude Sonnet 5.5 is now available on all platforms, including Amazon Web Services, Google Cloud, and Microsoft Azure."

Claude Sonnet 5.5 is now available on all platforms, including Amazon Web Services, Google Cloud, and Microsoft Azure.
Anthropic says that in its own testing Sonnet 5.5 costs up to 30 percent less per task than its predecessor.
Toned down to what the source says
In our testing, it costs up to 30% less per task than its predecessor.
Anthropic reports Sonnet 5.5 scores 70.6 percent on Terminal-Bench 4.0, against 10.3 percent for Sonnet 5. Quote: "Sonnet 5.5 scores 70.6% on Terminal-Bench 4.0, an agentic coding evaluation, compared to Sonnet 5"

Sonnet 5.5 scores 70.6% on Terminal-Bench 4.0, an agentic coding evaluation, compared to Sonnet 5’s 10.3%.
Anthropic says Sonnet 5.5 generates outputs 30%+ faster than Sonnet 5. Quote: "Sonnet 5.5 generates outputs 30%+ faster than Sonnet 5, making it our fastest Sonnet model to date."

Sonnet 5.5 generates outputs 30%+ faster than Sonnet 5, making it our fastest Sonnet model to date.

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