Deprecated. Released September 29, 2025.

Claude Sonnet 4.5 is deprecated: it is still functional but no longer recommended, and retires on November 30, 2026. Recommended replacement: Claude Sonnet 5.5. See Claude Sonnet 5.5 · Migrate to Claude Sonnet 5.5

Model ID: claude-sonnet-4-5-20250929

Context window: 200K tokens · Max output: 64K tokens · Input pricing: $3 / MTok · Output pricing: $15 / MTok

Announcement

与当前产品阵容的比较

Model Context Max output Price / MTok Thinking Default effort Knowledge cutoff
Claude Fable 5.1 1M 128K $10 / $50 Adaptive (always on) high Jun 2026
Claude Opus 5.5 1M 128K $4 / $20 Adaptive (always on) medium Jun 2026
Claude Sonnet 5.5 1M 128K $2 / $10 Adaptive high Jun 2026
Claude Sonnet 4.5 (this model) 200K 64K $3 / $15 Extended — Jan 2025
Claude Haiku 5.5 1M 128K From $0.10 / $0.50 Adaptive medium Jun 2026
  • Context: 1M tokens is roughly 555k words or 2.5M Unicode characters on the current tokenizer (introduced with Claude Opus 4.7); models before it fit about 750k words in 1M tokens. 200k tokens is roughly 150k words.
  • Max output: Synchronous Messages API limit. On the Message Batches API, Claude Opus 5.5, Claude Opus 5, Claude Sonnet 5.5, Claude Sonnet 5, Claude Haiku 5.5, Claude Opus 4.8, Claude Opus 4.7, Claude Opus 4.6, and Claude Sonnet 4.6 support up to 300k output tokens with the output-300k-2026-03-24 beta header.
  • Price / MTok: Input / output, base price per million tokens. Batch API requests are 50% off; prompt caching reads cost 10% of the base input price (2.5% on Claude Fable 5.1 and Claude Mythos 5.1, 5% on Claude Opus 5.5 and Claude Sonnet 5.5). See Pricing for the full list.
  • Thinking: Adaptive thinking lets the model decide how much to think, steered by effort. Extended thinking is the manual budget_tokens mode on earlier models.
  • Default effort: The effort parameter’s default on the Claude API. Models without a value don’t support the parameter.
  • Knowledge cutoff: Reliable knowledge cutoff: the date through which the model’s knowledge is most extensive and reliable.

规格

Model IDs

Platform Model ID
Claude API claude-sonnet-4-5-20250929
Claude API alias claude-sonnet-4-5
Amazon Bedrock (InvokeModel) anthropic.claude-sonnet-4-5-20250929-v1:0
Claude Models on Google Cloud (Google managed) claude-sonnet-4-5@20250929
Microsoft Foundry claude-sonnet-4-5
Claude Platform on AWS claude-sonnet-4-5
Claude Models on Google Cloud (Anthropic managed) claude-sonnet-4-5-20250929

Pricing

Feature Value
Input $3 / MTok
Output $15 / MTok
5m cache write $3.75 / MTok
1h cache write $6 / MTok
Cache read $0.30 / MTok
Batch API 50% discount on input and output

Full price list

Capabilities

Feature Value
Context window 200K tokens
Max output 64K tokens
Thinking Extended
Default effort Not supported
Input → output Text and images → text
Reliable knowledge cutoff Jan 2025
Training data cutoff Jul 2025

Availability

Feature Value
Status Deprecated
Released September 29, 2025
Deprecated September 30, 2026
Retires November 30, 2026
Platforms Claude API, Amazon Bedrock (InvokeModel), Claude Models on Google Cloud (Google managed), Microsoft Foundry, Claude Platform on AWS, Claude Models on Google Cloud (Anthropic managed)

资源

参考