Claude Opus 4.5 vs GPT-5.1 Instant
Wins 2 of 4 areas
Coding · Following instructions
Wins 2 of 4 areas
Reasoning · Images and charts
The two are evenly matched.Claude Opus 4.5 is better at coding and following instructions; GPT-5.1 Instant at reasoning and images and charts.
Scores updated · 6 tests both models report · How we compare
Where each one wins
Tests won in each of the four areas where both have results. 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 software10Claude Opus 4.51 of 1 test
- Following instructionsDoing exactly what it is asked10Claude Opus 4.51 of 1 test
- ReasoningHard problems that need careful thinking01GPT-5.1 Instant1 of 1 test
- Images and chartsUnderstanding pictures, charts and video01GPT-5.1 Instant1 of 1 test
Coding, reasoning, images and charts 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.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where Claude Opus 4.5 pulls ahead
- Keeps track of context across a multi-turn chatMulti-Challenge+7.8points ahead
- Fixes real GitHub issues in Python projectsSWE-bench Verified+4.6points ahead
Where GPT-5.1 Instant pulls ahead
- College exam questions with charts, maps and diagramsMMMU+4.7points ahead
- Graduate-level biology, physics and chemistry questionsGPQA Diamond+1.5points ahead
Every test, side by side
All 6 tests both models report. The winning score is in its model's colour; marks a score checked independently.
Images and chartsGPT-5.1 Instant
- MMMUGPT-5.1 Instant by 4.780.785.4+4.7
Following instructionsClaude Opus 4.5
- Multi-ChallengeClaude Opus 4.5 by 7.85951.2+7.8
Other results2 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.
- τ²-Bench (Retail)Claude Opus 4.5 by 1188.977.9+11
- AIME 2025GPT-5.1 Instant by 1.292.894+1.2
Questions people ask
Which is better, Claude Opus 4.5 or GPT-5.1 Instant?
Claude Opus 4.5 and GPT-5.1 Instant each win two of the four areas where both have results. Claude Opus 4.5 wins coding and following instructions; GPT-5.1 Instant wins reasoning and images and charts.
Which is better for coding?
Claude Opus 4.5. It wins the one coding test both models report.
How do you compare the two?
We use the 6 benchmark tests both models have published scores on. The verdict counts the 4 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 2 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.