specs at a glance
| Leaderboard status | Verifying — no confirmed SWE-bench Verified score |
|---|---|
| SWE-bench Verified | — |
| SWE-bench Pro | — |
| Terminal-Bench | 70.6 (TB4, vendor) |
| Input price / 1M | $2 |
| Output price / 1M | $10 |
| Context window | — |
| Open weights | No |
| Access | API (claude-sonnet-5-5) · Claude Platform · AWS · Google Cloud · Microsoft Azure |
| Maker | Anthropic |
how good is Claude Sonnet 5.5 at coding?
Claude Sonnet 5.5 is on our board but deliberately unranked. We rank by SWE-bench Verified, Anthropic has not published that number, and no independent evaluation has run it, so there is nothing here we could stand behind. What the maker does publish is 70.6 (TB4, vendor) on Terminal-Bench, measured on its own scaffold and not comparable like-for-like with the ranked rows. It moves into the ranking the moment a confirmed score exists. Terminal-Bench (agentic terminal work): 70.6 (TB4, vendor).
Score provenance: Vendor-reported (Anthropic, Sept 28 2026): Terminal-Bench 4.0 70.6%, FrontierCode 1.1 46.2% (max effort), CursorBench 4.0 55.5%, GDPval-AA v2.1 1844 Elo, OSWorld 2.1 80.1% (partial credit). Anthropic published NO SWE-bench Verified score for this model, continuing the pivot away from that metric it started with Opus 5.5.
List pricing is unchanged from Sonnet 5 at $2/$10 per 1M tokens; Anthropic's '30% cheaper per task' claim is a total-cost-per-completed-job figure driven by a stated 30%+ speed gain and fewer output tokens, not a rate cut. Queue caveat: vals.ai archived its SWE-bench Verified board on 5 September 2026, so this row is unlikely to ever receive an independent score from that source. See /p/claude-sonnet-5-5-launch/.
what does Claude Sonnet 5.5 cost?
$2 per 1M input tokens and $10 per 1M output — as listed by the maker. Coding workloads are output-heavy, so weight the output rate when budgeting. Run your own volume through the AI API cost calculator for a monthly estimate.
where can you use it?
Available via API (claude-sonnet-5-5) · Claude Platform · AWS · Google Cloud · Microsoft Azure. As a proprietary model, you're on the maker's infrastructure and release schedule.
Full storyAnthropic Launches Claude Sonnet 5.5, Cuts Task Costs 30%
Ranked on our AI Coding Leaderboard — scores confirmed against primary sources only, updated 2026-09-28.