One agent session
1M input tokens and 100K output tokens, no caching.
- Input1M x $3 = $3.00
- Output0.1M x $15 = $1.50
$4.50per session
Anthropic - Closed weights
Claude Sonnet 4.5 pricing and specs
Claude Sonnet 4.5 is a closed-weights model from Anthropic that costs $3 per 1M input tokens and $15 per 1M output tokens on the first-party API, with a 200K-token context window.
Last verified from platform.claude.com. All sources
- Input / 1M
- $3
- Output / 1M
- $15
- Context
- 200K tokens
- Weights
- Closed
Pricing per 1M tokens
| Item | Price / 1M tokens |
|---|---|
| Input | $3 |
| Output | $15 |
| Cache read | $0.30 |
| Cache write (5 minutes) | $3.75 |
| Cache write (1 hour) | $6 |
| Batch inputBatch requests | $1.50 |
| Batch outputBatch requests | $7.50 |
Note: Deprecated 2026-09-30; retires on the Claude API on 2026-11-30 (recommended replacement claude-sonnet-5-5). Claude API alias is claude-sonnet-4-5. First-party context window is 200K; the Vercel AI Gateway lists 1M for this id, which this dataset does not use.
Specs
- Context window
- 200,000 tokens
- Max output
- 64,000 tokens
- Release date
- Provider
- Anthropic
- API model id
claude-sonnet-4-5-20250929- Vercel AI Gateway id
anthropic/claude-sonnet-4.5- Weights
- Closed weights
What Claude Sonnet 4.5 costs in practice
Worked from the standard list rates above, with the math shown so you can swap in your own token counts.
A chat app
10,000 requests a day at 2K input and 500 output tokens each.
- Input20M x $3 = $60.00
- Output5M x $15 = $75.00
$135.00per day
$4,050.00 per 30-day month
The same session at a 90% cache hit
90% of the input is read from the prompt cache. The one-time cache write premium is not included.
- Cached input0.9M x $0.30 = $0.27
- Uncached input0.1M x $3 = $0.30
- Output0.1M x $15 = $1.50
$2.07per session
Compare with
| Model | Input / 1M | Output / 1M |
|---|---|---|
| Claude Sonnet 4.5 (this page) | $3 | $15 |
| Claude Sonnet 4.6Anthropic | $3 | $15 |
| GPT-5.4OpenAI | $2.50 | $15 |
| Kimi K3Moonshot AI | $3 | $15 |
| GPT-5.2OpenAI | $1.75 | $14 |
| Claude Opus 5.5Anthropic | $4 | $20 |
| Claude Sonnet 5Anthropic | $2 | $10 |
| Claude Sonnet 5.5Anthropic | $2 | $10 |
| Claude Haiku 4.5Anthropic | $1 | $5 |
| Claude Opus 4.5Anthropic | $5 | $25 |
Related reading
- Anthropic Sonnet 4.5 in Claude CodeClaude Sonnet 4.5 in Claude Code uses parallel subagents to build a Next.js site and ten arcade games from three prompts. What worked and what still broke.
- Claude Agent SDK in Late 2026: What Is New and How to Use ItWhat changed in the Claude Agent SDK by October 2026: nested subagents with caps, SessionStore, skills, plugins, structured outputs and permission defaults.
- Claude API OpenTelemetry Tracing: How to Set It Up (Beta)The Claude API now exports OpenTelemetry traces in beta. Set up SDK spans in code, add a Console destination for API spans, and count tokens once.
- Claude Code Idle Compaction: What It Does and How to Turn It OffClaude Code 2.1.299 compacts sessions over 200K tokens after about 54 idle minutes. How the cache math works, the setting to turn it off, and when to keep it.
- Tool Calling Under the Hood: Claude Messages vs OpenAI ResponsesHow tool calling works on the wire: JSON schema tools, parallel calls, tool_choice, strict mode and streaming deltas in Claude Messages vs OpenAI Responses.
- Claude Code Desktop SneakPeek Flaw: Fixed Version and What To DoSneakPeek (CVSS 8.7) let a poisoned HTML file read SSH keys and cloud credentials via the Claude Code Desktop preview pane. Fixed in Claude Desktop 1.30096.1.
FAQ
How much does Claude Sonnet 4.5 cost per million tokens?
Claude Sonnet 4.5 costs $3 per 1M input tokens and $15 per 1M output tokens on Anthropic's first-party API, per platform.claude.com on October 17, 2026. Per 1M tokens, cache reads cost $0.30, and the batch rate is $1.50 input and $7.50 output.
What is Claude Sonnet 4.5's context window?
Claude Sonnet 4.5 has a 200,000-token context window and returns up to 64,000 output tokens per response.
Are Claude Sonnet 4.5's weights open?
No. Claude Sonnet 4.5 is a closed-weights model. You call it through Anthropic's API as claude-sonnet-4-5-20250929 or through Vercel AI Gateway as anthropic/claude-sonnet-4.5.
When was Claude Sonnet 4.5 released?
Anthropic released Claude Sonnet 4.5 on September 29, 2025.
Sources
Last verified from platform.claude.com.
- https://platform.claude.com/docs/en/about-claude/pricing
- https://platform.claude.com/docs/en/models/sonnet-4-5/overview
- https://platform.claude.com/docs/en/about-claude/models/overview
- https://platform.claude.com/docs/en/release-notes/overview
- https://platform.claude.com/docs/en/about-claude/model-deprecations
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