Claude Opus 5.5 vs GPT-6.1 Sol
Wins 5 of 8 areas
Coding · Agents · Reasoning · Images and charts · Long documents
Wins 3 of 8 areas
Facts · Math · Following instructions
Claude Opus 5.5 is the stronger all-rounder.GPT-6.1 Sol is cheaper and better at math.
Both rank among the ten best models we track in reasoning, facts and math.
Scores updated · 33 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 software40Claude Opus 5.54 of 4 tests
- AgentsCarrying out multi-step tasks on its own20Claude Opus 5.52 of 2 tests
- Images and chartsUnderstanding pictures, charts and video20Claude Opus 5.52 of 2 tests
- ReasoningHard problems that need careful thinking21Claude Opus 5.52 of 5 tests · 2 ties
- Long documentsFinding answers in very long texts10Claude Opus 5.51 of 1 test
- MathCompetition and research-level math02GPT-6.1 Sol2 of 3 tests · 1 tie
- FactsGetting facts right instead of making them up12GPT-6.1 Sol2 of 3 tests
- Following instructionsDoing exactly what it is asked01GPT-6.1 Sol1 of 1 test
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.
GPT-6.1 Sol costs 81% less for the same work.
The biggest differences
The three tests each model wins by the widest margin. Scores are out of 100.
Where Claude Opus 5.5 pulls ahead
- Fixes real GitHub issues, working as an agentLiveBench · Agentic Coding+17.1points ahead
- Real work tasks from 44 professionsGDPVal+13.6points ahead
- Code for real scientific research problemsSciCode+12.7points ahead
Where GPT-6.1 Sol pulls ahead
- Follows detailed instructions exactlyLiveBench · Instruction Following+8.5points ahead
- Extremely hard research-level math problemsFrontierMath Tier 4+5points ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+4.3points ahead
Every test, side by side
All 33 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Opus 5.5
- LiveBench · Agentic CodingClaude Opus 5.5 by 17.171.754.5+17.1
- SciCodeClaude Opus 5.5 by 12.766.954.2+12.7
- LiveBench · CodingClaude Opus 5.5 by 8.989.380.4+8.9
- LMArena · WebDevClaude Opus 5.5 by 58 rating points18071749+58 rating
AgentsClaude Opus 5.5
- GDPValClaude Opus 5.5 by 13.668.354.7+13.6
- Terminal-Bench 4.0Claude Opus 5.5 by 3.559.656.1+3.5
ReasoningClaude Opus 5.5
- Humanity's Last ExamClaude Opus 5.5 by 8.561.452.9+8.5
- SimpleBenchClaude Opus 5.5 by 5.588.482.9+5.5
- ARC-AGI-2GPT-6.1 Sol by 2.591.794.2+2.5
- LiveBench · Reasoningtie92.292.6tie
- CritPttie31.731.7tie
FactsGPT-6.1 Sol
- AA-Omniscience · Non-hallucinationGPT-6.1 Sol by 4.341.445.7+4.3
- AA-Omniscience · AccuracyClaude Opus 5.5 by 4.166.262.1+4.1
- SimpleQA VerifiedGPT-6.1 Sol by 1.772.273.9+1.7
Images and chartsClaude Opus 5.5
- LMArena · VisionClaude Opus 5.5 by 33 rating points13211288+33 rating
- MMMU-ProClaude Opus 5.5 by 1.787.786+1.7
MathGPT-6.1 Sol
- FrontierMath Tier 4GPT-6.1 Sol by 595100+5
- FrontierMath Tiers 1-3 (v2)GPT-6.1 Sol by 2.591.293.7+2.5
- LiveBench · Mathematicstie97.196.8tie
Following instructionsGPT-6.1 Sol
- LiveBench · Instruction FollowingGPT-6.1 Sol by 8.565.774.2+8.5
Other results12 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.
- OSWorld 2.0Claude Opus 5.5 by 10.481.871.4+10.4
- Terminal-Bench 4.0Claude Opus 5.5 by 8.266.458.2+8.2
- AA IntelligenceClaude Opus 5.5 by 5.857.651.8+5.8
- AA-OmniscienceClaude Opus 5.5 by 4.946.441.5+4.9
- livebench_languageGPT-6.1 Sol by 3.886.390.1+3.8
- HiL-Bench (Tools-allowed)GPT-6.1 Sol by 3.35962.3+3.3
- livebench_data_analysisGPT-6.1 Sol by 2.480.382.7+2.4
- HealthBenchClaude Opus 5.5 by 2.160.658.5+2.1
- Terminal-Bench-Science 0.1Claude Opus 5.5 by 1.758.757+1.7
- HealthBench ProfessionalClaude Opus 5.5 by 1.465.664.2+1.4
- ARC-AGI-1Claude Opus 5.5 by 197.596.5+1
- DeepSWE 1.1GPT-6.1 Sol by 174.275.2+1
Questions people ask
Which is better, Claude Opus 5.5 or GPT-6.1 Sol?
Claude Opus 5.5 wins five of the eight areas we test: coding, agents, reasoning, images and charts and long documents. GPT-6.1 Sol wins facts, math and following instructions, and costs 81% less.
Which is better for coding?
Claude Opus 5.5. It wins 4 of the 4 coding tests both models report; GPT-6.1 Sol wins none.
Which is cheaper?
Claude Opus 5.5 costs $4.00 per million input tokens and $20.00 per million output tokens; GPT-6.1 Sol costs $2.00 and $2.50. That makes GPT-6.1 Sol about 81% cheaper for the same work.
How do you compare the two?
We use the 33 benchmark tests both models have published scores on. The verdict counts the 21 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 12 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.