Head-to-head · Updated Nov 3, 2026
Claude Opus 5.5 vs Claude Sonnet 5.5
Anthropic’s Claude Opus 5.5 and Anthropic’s Claude Sonnet 5.5 on independent tests for professional work, cost and speed.
Short answer
Claude Opus 5.5 leads on 10 of 13 quality scores, including the overall Intelligence Index.
- FinanceClaude Opus 5.559.4 vs 55.8
- Legal workClaude Opus 5.558.0 vs 52.2
- HealthcareClaude Opus 5.557.9 vs 54.2
- EngineeringClaude Opus 5.564.6 vs 58.2
- Strategy & operationsClaude Opus 5.561.4 vs 58.1
- Coding agentsClaude Sonnet 5.563.6% vs 59.6%
- Expert knowledgeClaude Opus 5.561.4% vs 55.0%
- Fewer made-up answersClaude Sonnet 5.543.3% vs 50.3%
- Lower costClaude Sonnet 5.5$7,981 vs $8,910
- SpeedClaude Sonnet 5.5140 tok/s vs 96 tok/s
Scores, cost and speed
| Measure | Claude Opus 5.5 (Max, Default Fallback) | Claude Sonnet 5.5 (Max, Default Fallback) |
|---|---|---|
| Overall | ||
| Intelligence IndexCombined score across nine evaluations | Leads: 58.4 | 54.2 |
| Professional work | ||
| Finance & accounting | Leads: 59.4 | 55.8 |
| Legal | Leads: 58.0 | 52.2 |
| Healthcare & medical | Leads: 57.9 | 54.2 |
| Engineering | Leads: 64.6 | 58.2 |
| Strategy & operations | Leads: 61.4 | 58.1 |
| Economics | Leads: 62.3 | 56.0 |
| Specific tests | ||
| Terminal-Bench 4.0Agentic coding tasks | 59.6% | Leads: 63.6% |
| FrontierCode 2.0Hard programming problems | Leads: 46.4% | 41.7% |
| Humanity’s Last ExamExpert-level questions | Leads: 61.4% | 55.0% |
| HealthBenchHealth conversations graded by physicians’ rubrics | 57.0% | Leads: 62.1% |
| GDPval-AAKnowledge-work deliverables, Elo | Leads: 1866 | 1838 |
| Hallucination rateAA-Omniscience; lower is better | 50.3% | Leads: 43.3% |
| Cost & speed | ||
| Input priceUS$ per 1M tokens | $4 | Leads: $2 |
| Output priceUS$ per 1M tokens | $20 | Leads: $10 |
| Cost to run the indexUS$, includes reasoning tokens | $8,910 | Leads: $7,981 |
| Output speedMedian tokens per second | 96 tok/s | Leads: 140 tok/s |
| Context windowTokens | 1M | 1M |
Scores, prices and speeds: Artificial Analysis, independently measured, checked Nov 3, 2026. Model names include the tested reasoning setting. Stubbi has not rerun these evaluations. Consumer apps such as ChatGPT, Claude and Gemini may use other models and add features like search and memory.
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