Claude Sonnet
Open timelineCurrent models
Official catalog- Claude Sonnet 5.5
Claude Sonnet 5.5
Sonnet 5.5 targets everyday coding, bug fixes and document creation.
- API model ID: claude-sonnet-5-5
Access at announcement
Available across Claude platforms. Haiku 5.5 remains forthcoming in this announcement.
Announcements & evaluations
8 sourcesThe official Anthropic account confirms Claude Sonnet 5.5 is available and quotes the product account announcement.
Current leaderboards
Intelligence Index v4.3.2. This is a checked snapshot; older method versions are not directly comparable.
View scoresUpdate date not stated
Update date not stated
| Claude Opus 5.5max with fallback | 58 |
|---|---|
| Claude Sonnet 5.5max with fallback | 56 |
| GPT-6 Astramax | 53 |
| Gemini 4 Argonhigh | 53 |
| GPT-6.1 Solmax | 52 |
| Qwen3.8 Max (0902) | 45 |
| Muse Spark 1.3max | 48 |
| GLM-5.3max | 45 |
| GLM-5.3low | 34 |
| GLM-5.3-Flash | 42 |
Text preference scores. Preliminary entries and uncertainty are retained; compare within this board.
View scoresOct 2, 2026
Data updated ·
| Gemini 4 Argonhigh; preliminary | 1525±9 |
|---|---|
| Claude Opus 5.5high | 1504±9 |
| Claude Fable 5.1max | 1501±6 |
| Gemini 3.8 Flashhigh; preliminary | 1495±5 |
| Muse Spark 1.3max | 1494±6 |
WebDev preference scores. Preliminary entries and uncertainty are retained; compare within this board.
View scoresOct 1, 2026
Data updated ·
| Claude Opus 5.5max | 1815+16/-16 |
|---|---|
| Claude Sonnet 5.5xhigh | 1786+18/-18 |
| GPT-6.1 Solmax | 1758+17/-17 |
| Gemini 4 Argonhigh; preliminary | 1680+13/-13 |
| Qwen3.8 Max (0902)preliminary | 1670+8/-8 |
Agent Arena measures Net Improvement, not task success rate. Scores depend on the listed configuration.
View scoresOct 2, 2026
Data updated ·
| Claude Fable 5.1max | 14.31%±1.90% |
|---|---|
| Claude Opus 5.5high | 13.82%±2.17% |
| Claude Sonnet 5.5max | 12.52%±3.09% |
| GPT-6 Astramax | 12.27%±2.23% |
| GPT-6.1 Solmax | 11.23%±2.76% |
TH1.1 task-completion time horizons. Model-specific chart values were not read; no scores are copied.
Data updated ·
Family-wide source1
These sources cover the model family or historical versions. They do not evaluate this release.