Claude Opus 4.6 vs Claude Sonnet 5.5
Wins 2 of 8 areas
Images and charts · Following instructions
Wins 6 of 8 areas
Coding · Agents · Reasoning · Facts · Math · Long documents
Claude Sonnet 5.5 is the stronger all-rounder.Claude Opus 4.6 is better at images and charts.
Scores updated · 32 tests both models report · How we compare
Where each one wins
Tests won in each of the eight areas we test. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- CodingWriting and fixing software06Claude Sonnet 5.56 of 6 tests
- ReasoningHard problems that need careful thinking06Claude Sonnet 5.56 of 6 tests
- MathCompetition and research-level math03Claude Sonnet 5.53 of 3 tests
- FactsGetting facts right instead of making them up02Claude Sonnet 5.52 of 3 tests · 1 tie
- AgentsCarrying out multi-step tasks on its own01Claude Sonnet 5.51 of 1 test
- Long documentsFinding answers in very long texts01Claude Sonnet 5.51 of 1 test
- Images and chartsUnderstanding pictures, charts and video10Claude Opus 4.61 of 1 test
- Following instructionsDoing exactly what it is asked10Claude Opus 4.61 of 1 test
Agents, images and charts, long documents and following instructions rest on a single test each.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
Claude Sonnet 5.5 costs 60% less for the same work.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where Claude Sonnet 5.5 pulls ahead
- Extremely hard research-level math problemsFrontierMath Tier 4+53.7points ahead
- Long, multi-file coding tasks in real codebasesSWE-bench Pro+27.9points ahead
- Solves new puzzle games it has never seenARC-AGI-3+23.8points ahead
Where Claude Opus 4.6 pulls ahead
- Follows detailed instructions exactlyLiveBench · Instruction Following+6.5points ahead
Every test, side by side
All 32 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Sonnet 5.5
- SWE-bench ProClaude Sonnet 5.5 by 27.953.481.3+27.9
- LMArena · WebDevClaude Sonnet 5.5 by 224 rating points15461770+224 rating
- LiveBench · CodingClaude Sonnet 5.5 by 13.278.291.4+13.2
- SWE-bench MultilingualClaude Sonnet 5.5 by 12.577.890.3+12.5
- SciCodeClaude Sonnet 5.5 by 9.151.961+9.1
- LiveBench · Agentic CodingClaude Sonnet 5.5 by 7.34956.3+7.3
ReasoningClaude Sonnet 5.5
- ARC-AGI-3Claude Sonnet 5.5 by 23.80.524.3+23.8
- CritPtClaude Sonnet 5.5 by 18.812.631.4+18.8
- ARC-AGI-2Claude Sonnet 5.5 by 15.168.883.9+15.1
- Humanity's Last ExamClaude Sonnet 5.5 by 15.139.955+15.1
- SimpleBenchClaude Sonnet 5.5 by 8.367.675.9+8.3
- LiveBench · ReasoningClaude Sonnet 5.5 by 2.988.791.6+2.9
FactsClaude Sonnet 5.5
- AA-Omniscience · Non-hallucinationClaude Sonnet 5.5 by 15.837.253+15.8
- AA-Omniscience · AccuracyClaude Sonnet 5.5 by 74754+7
- SimpleQA Verifiedtie4746.5tie
Images and chartsClaude Opus 4.6
- LMArena · VisionClaude Opus 4.6 by 29 rating points13161287+29 rating
MathClaude Sonnet 5.5
- FrontierMath Tier 4Claude Sonnet 5.5 by 53.726.880.5+53.7
- FrontierMath Tiers 1-3 (v2)Claude Sonnet 5.5 by 22.86688.8+22.8
- LiveBench · MathematicsClaude Sonnet 5.5 by 6.889.396.1+6.8
Following instructionsClaude Opus 4.6
- LiveBench · Instruction FollowingClaude Opus 4.6 by 6.563.356.8+6.5
Other results10 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- SWE-bench MultimodalClaude Sonnet 5.5 by 27.227.154.3+27.2
- AA IntelligenceClaude Sonnet 5.5 by 24.131.956+24.1
- AA-OmniscienceClaude Sonnet 5.5 by 18.613.732.3+18.6
- HLE (with tools)Claude Sonnet 5.5 by 11.253.364.5+11.2
- livebench_data_analysisClaude Opus 4.6 by 10.469.959.5+10.4
- OfficeQA ProClaude Sonnet 5.5 by 8.557.165.6+8.5
- Legal Agent BenchmarkClaude Sonnet 5.5 by 7.54.211.7+7.5
- livebench_languageClaude Opus 4.6 by 5.383.378+5.3
- ARC-AGI-1Claude Sonnet 5.5 by 3.59396.5+3.5
- OfficeQAClaude Sonnet 5.5 by 3.473.576.9+3.4
Questions people ask
Which is better, Claude Opus 4.6 or Claude Sonnet 5.5?
Claude Sonnet 5.5 wins six of the eight areas we test: coding, agents, reasoning, facts, math and long documents. Claude Opus 4.6 wins images and charts and following instructions.
Which is better for coding?
Claude Sonnet 5.5. It wins 6 of the 6 coding tests both models report; Claude Opus 4.6 wins none.
Which is cheaper?
Claude Opus 4.6 costs $5.00 per million input tokens and $25.00 per million output tokens; Claude Sonnet 5.5 costs $2.00 and $10.00. That makes Claude Sonnet 5.5 about 60% cheaper for the same work.
How do you compare the two?
We use the 32 benchmark tests both models have published scores on. The verdict counts the 22 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 10 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.