Claude Sonnet 4.5

Claude Sonnet 4.5 is a balanced Claude model for coding, analysis, agent workflows, and cost control, per Anthropic. It is the first version of the claude-sonnet line in the registry. It has a 1,000,000-token context window and a 64,000-token maximum output. Pricing starts at $0.43 per million input tokens and $2.14 per million output tokens, with cached input at $0.30 per million tokens. The weights are not open. It supports reasoning mode, tool calling, and accepts image, PDF, and text inputs, returning text.

First version of its line in the registry.

Range across the hosts that serve it: up to $3.75 per 1M input tokens.

• ·1M token context window
• ·64K token max output
• ·Reasoning mode enabled
• ·Tool calling supported
• ·Accepts image, PDF, and text

• Reach for it for coding tasks
• Reach for it for data analysis
• Reach for it for agent workflows
• Reach for it for cost control

24 hosts serve this model at the price above · the maker's documentation

• 7I Benchmarked 4 Frontier LLMs on Catching ML's "Silent Killers": DeepSeek-R1 Missed the Most Basic Bug2026-10-03
• 7From Playground to Caching: Learning Amazon Bedrock2026-09-28
• 8UN turns to Google to make its global data ready for AI agents2026-09-18

3 signals of the archive mention this model, each scored against the published bar. This list is rebuilt from the archive at every build, so it cannot go stale.

The registry keeps the six most recent versions of a line. Older ones stay in the file and can be surfaced without a rebuild.

What is the context window?

The context window is 1,000,000 tokens.

Are the weights open?

No, the weights are not open.

What input formats does it accept?

It accepts image, PDF, and text inputs, and returns text.