Claude Sonnet 4.5 (2025-09-29)

Latest Claude Sonnet with improved reasoning and extended thinking.

claude-sonnet-4-5-20250929
STABLEGet StartedView uptime
200,000 context
Released September 29, 2025
Starting at $2.85/M (5% off) input tokens
Starting at $14.25/M (5% off) output tokens
Streaming
Vision
Tools
Reasoning
Structured JSON
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5% offthis model via Anthropic

All Providers for Claude Sonnet 4.5 (2025-09-29)

OffRail routes requests to the best providers that are able to handle your prompt size and parameters.

Anthropic
Context: 200k5% off
Input
$3$2.85
5% off
/M tokens
Cache Read
$0.3$0.285
5% off
/M tokens
Output
$15$14.25
5% off
/M tokens
Cache Write 5m
$3.75$3.5625
5% off
/M tokens
Cache Write 1h
$6$5.7
5% off
/M tokens
+ $0.010$0.009 per search
Get Started
AWS Bedrock
Context: 200k
Input
$3
/M tokens
Cache Read
$0.3
/M tokens
Output
$15
/M tokens
Cache Write 5m
$3.75
/M tokens
Cache Write 1h
$6
/M tokens
Get Started

Frequently asked questions

What is Claude Sonnet 4.5 (2025-09-29)?

Latest Claude Sonnet with improved reasoning and extended thinking. You can access it through OffRail's OpenAI-compatible API with automatic provider routing, fallback, and cost analytics.

How much does Claude Sonnet 4.5 (2025-09-29) cost?

Pricing for Claude Sonnet 4.5 (2025-09-29) on OffRail starts at $3.00 per million input tokens and $15.00 per million output tokens, depending on the provider. The pricing table above always reflects the current per-provider rates.

What is the context length of Claude Sonnet 4.5 (2025-09-29)?

Claude Sonnet 4.5 (2025-09-29) supports a context window of up to 200,000 tokens on its largest provider deployment.

Which providers serve Claude Sonnet 4.5 (2025-09-29)?

Claude Sonnet 4.5 (2025-09-29) is served by Anthropic, AWS Bedrock through OffRail. Requests are automatically routed to the best available provider, with fallback when a provider has issues.

Does Claude Sonnet 4.5 (2025-09-29) support tool calling and structured outputs?

Yes. Claude Sonnet 4.5 (2025-09-29) supports both tool (function) calling and strict JSON output schema (upstream-enforced) through OffRail.

When was Claude Sonnet 4.5 (2025-09-29) released?

Claude Sonnet 4.5 (2025-09-29) was released on September 29, 2025.