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Models / Anthropic

Claude Sonnet 4.5

GA

API ID claude-sonnet-4-5-20250929 (alias claude-sonnet-4-5). Listed under 'Legacy models' on overview but Active in deprecations table. Extended thinking: Yes; adaptive thinking: No. 200k context, max output 64k. 5m cache $3.75, 1h cache $6, cache hits $0.30/MTok. Batch $1.50/$7.50. Reliable knowledge cutoff Jan 2025; training data cutoff Jul 2025. Snapshot 20250929 implies Sep 29, 2025 release. Tentative retirement not sooner than September 29, 2026.

Claude Sonnet 4.5 by Anthropic costs $3 per 1M input tokens and $15 per 1M output tokens ($6/1M blended), with a 200K (200.000-token) context window. It is generally available (GA), with a knowledge cutoff of Jan 2025.

Last verified: 13 Aug 2026 · sourced from official provider documentation

Provider
Anthropic
Status
GA
Input price
$3 / 1M tokens
Output price
$15 / 1M tokens
Cached input
$0.3 / 1M tokens
Blended price
$6 / 1M tokens
Context window
200.000 tokens (200K)
Max output
64.000 tokens
Modality
text, image, vision
Open weights
No — API only
Knowledge cutoff
2025-01
Released
—
API string
claude-sonnet-4-5-20250929

Source: Anthropic official documentation ↗

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FAQ

Claude Sonnet 4.5 — questions & answers

How much does Claude Sonnet 4.5 cost?

Claude Sonnet 4.5 is priced at $3 per 1M input tokens and $15 per 1M output tokens ($6/1M blended at a 3:1 input-to-output ratio), with cached input at $0.3 per 1M tokens.

What is the context window of Claude Sonnet 4.5?

Claude Sonnet 4.5 has a 200.000-token context window (200K), with up to 64.000 output tokens per request.

Is Claude Sonnet 4.5 deprecated?

No — Claude Sonnet 4.5 is generally available (GA) and not currently scheduled for deprecation or retirement in our tracker.

Does Claude Sonnet 4.5 support image or vision input?

Yes — Claude Sonnet 4.5 accepts image input. Listed modalities: text, image, vision.

Can I self-host Claude Sonnet 4.5?

No — Claude Sonnet 4.5 is proprietary. Its weights are not publicly released, so it is available only through Anthropic's API (or hosted partners), not for self-hosting.

What is the API model string for Claude Sonnet 4.5?

The API model identifier for Claude Sonnet 4.5 is "claude-sonnet-4-5-20250929" when calling Anthropic's API.

What is Claude Sonnet 4.5's knowledge cutoff?

Claude Sonnet 4.5's training knowledge cutoff is Jan 2025.