Claude Opus 5.5

System Card Table 8.1.A. AA-Briefcase v1.1 Elo at max effort (max_score 3000).

System Card §8.9. ArXivMath August 2026 (57 problems); without tools; max effort; averaged over four attempts per problem. Evaluated internally without safeguards classifiers.

Opus 5.5 with production safeguards enabled. Zapier AutomationBench; runs without fallback models, so safeguard interventions counted as failures. Adaptive thinking at max effort.

System Card §8.13.2. BenchCAD Vision2Code 1k subset; voxel IoU without tools; adaptive thinking at max effort; averaged over five runs.

System Card §8.13.2. BenchCAD Vision2Code 1k subset; voxel IoU with tools; adaptive thinking at max effort; averaged over five runs.

System Card §8.17.1. BioMysteryBench Human Solvable subset 89.3%; adaptive thinking at max effort; bash/file tools with package allow-list.

Opus 5.5 with production safeguards enabled. Chartography with tools; adaptive thinking at max effort.

Opus 5.5 with production safeguards enabled. CursorBench 4.0; adaptive thinking at max effort.

System Card §8.3. DeepSWE v1.1; 5-trial average. Adaptive thinking at max effort.

Opus 5.5 with production safeguards enabled. FrontierCode v1.1 Main subset; adaptive thinking at max effort.

System Card §8.7. FrontierSWE v2; Proximal harness; max effort; 5 trials per task; mean across trials.

Opus 5.5 with production safeguards enabled. GDPval-AA v2.1 Elo (max_score 3000); adaptive thinking at max effort.

System Card §8.16.1. GMMLU average accuracy 94.3% across 42 languages; adaptive thinking at max effort; single trial; no tools.

System Card §8.15.1. HealthBench length-adjusted score 60.6% (penalizes verbose responses); adaptive thinking at max effort; 5-trial average. Prefer length-adjusted over raw 68.1% to match other catalog models and avoid duplicate benchmark_id records.

System Card Table 8.1.A length-adjusted score 65.6% (prefer Table 8.1.A over §8.15.2 raw 77.1%). Adaptive thinking at max effort; 5-trial average; safety classifiers enabled with refusal fallback to Claude Opus 5. Length-adjusted per HealthBench Professional paper method.

System Card Table 8.1.A / §8.11.1. HLE no tools (reasoning-only); adaptive thinking at max effort. Alongside with-tools 67.7% already cataloged from the announcement table.

Opus 5.5 with production safeguards enabled. Humanity's Last Exam with tools; adaptive thinking at max effort.

System Card §8.17.2. LatchBio SingleCellBench 61.2%; adaptive thinking at max effort; bash/file tools.

System Card §8.17.2. LatchBio SpatialBench Verified 72.0%; adaptive thinking at max effort; bash/file tools.

System Card §8.14.2. Legal Agent Benchmark held-out set; all-pass rate 8.3% at max effort (AA harness). Mean criterion-pass rate 91.2% noted in card but not stored as a separate catalog metric (all-pass is the standard LAB reporting id).

System Card §8.16.2. MILU average accuracy 93.1% across 11 languages; adaptive thinking at max effort; averaged over 5 trials; no tools.

System Card §8.14.1. OfficeQA full set; max effort; mean of five runs; agentic harness with extracted-text documents and code-execution tools.

System Card §8.14.1. OfficeQA Pro (133-question subset); max effort; mean of five runs.

Opus 5.5 with production safeguards enabled. OSWorld 2.0 partial score (announcement reports partial, not strict); adaptive thinking at max effort.

System Card §8.10.1. ProgramBench 166 golden tasks; mini-swe-agent harness; no 6-hour time limit; hidden test pass rate against tests the reference binary passes.

System Card Table 8.1.A / §8.2. Adaptive thinking at max effort; 5-trial average. 300 problems across nine programming languages.

System Card Table 8.1.A / §8.2. Adaptive thinking at max effort; 5-trial average. Visual context (screenshots and design mockups).

System Card Table 8.1.A / §8.2. Adaptive thinking at max effort; 5-trial average. Production safeguards as in card capability summary.

Opus 5.5 with production safeguards enabled. Terminal-Bench 4.0 accuracy 66.4% at xhigh effort (Claude Code harness). Unless otherwise noted, other Opus 5.5 results on this announcement table use adaptive thinking at max effort; TB4 is explicitly reported at xhigh.

Opus 5.5 with production safeguards enabled. Terminal-Bench-Science 0.1; adaptive thinking at max effort.

System Card §8.14.5. Toolathlon Verified Pass@1 77.8% (3-trial average across 108 tasks). Adaptive thinking at max effort; safety/sandbox stops counted as failures.