Claude Sonnet 4.5 (2025-09-29)
- Context
- Not stated
- Not listed
- Input price
- $3.00
- per 1M tokens · Claude API
- Output price
- $15.00
- per 1M tokens
- Epoch Capabilities Index
- —
- Not listed
- LMArena Text
- —
- Not listed
Where to run it
1 offering · prices as listed| Meter | Tier | Price |
|---|---|---|
Claude API (opens in a new tab) Deprecated | ||
| Input | Standard | $3.00 / 1M tokens |
| Output | Standard | $15.00 / 1M tokens |
News
All news →- Sep 30, 2026 Anthropic schedules Claude Sonnet 4.5 retirement Anthropic plans to retire Claude Sonnet 4.5 (claude-sonnet-4-5-20250929) from the Claude API on November 30, 2026. It recommends migrating to Claude Sonnet 5.5.
Changes
All changes →- Now priced on Claude API Input $3.00 · Output $15.00
- New language model
Cited scores
From third-party leaderboards, not measured by us- Epoch AI · FrontierMath Tiers 1–3 23.9%
#60 of 74 listed models · 32K thinking budget · ±2.53
- Epoch AI · GPQA Diamond 82.3%
#63 of 128 listed models · 59K thinking budget · ±2.72
Also listed: 32K thinking budget 81.7% · 16K thinking budget 78.8% · claude-sonnet-4-5-20250929 73.7%
- Epoch AI · SWE-bench Verified 71.3%
#21 of 30 listed models · ±2.06
- Epoch AI, 'Capabilities & benchmarking'. Published online at epoch.ai. Retrieved from 'https://epoch.ai/benchmarks'. Licensed CC BY 4.0. · License · as of Oct 3, 2026
- Epoch AI, 'Capabilities & benchmarking'. Published online at epoch.ai. Retrieved from 'https://epoch.ai/benchmarks'. Licensed CC BY 4.0. · License · as of Oct 1, 2026
- changes we made