Claude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) vs Claude Opus 5
Wins 3 of 6 areas
Coding · Images and charts · Long documents
Wins 1 of 6 areas
Reasoning
Claude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) wins more areas, narrowly.Claude Opus 5 is better at reasoning.
Scores updated · 11 tests both models report · How we compare
Where each one wins
Tests won in each of the six 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 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback)1 of 1 test
- Images and chartsUnderstanding pictures, charts and video10Claude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback)1 of 1 test
- Long documentsFinding answers in very long texts10Claude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback)1 of 1 test
- ReasoningHard problems that need careful thinking01Claude Opus 51 of 2 tests · 1 tie
- AgentsCarrying out multi-step tasks on its own11Even1 each
- FactsGetting facts right instead of making them up11Even1 each
Coding, images and charts and long documents 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 Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) costs 20% 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 (Adaptive Reasoning, Medium Effort, Default Fallback) pulls ahead
- Reasons across sets of long documentsAA-LCR+5points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+3.7points ahead
- Complex command-line tasks across many fieldsTerminal-Bench 4.0+3.5points ahead
Where Claude Opus 5 pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+7.6points ahead
- Real work tasks from 44 professionsGDPVal+6.9points ahead
- Research-level physics problemsCritPt+1.4points ahead
Every test, side by side
All 11 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback)
- SciCodeClaude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) by 2.959.356.4+2.9
AgentsEven
- GDPValClaude Opus 5 by 6.954.361.2+6.9
- Terminal-Bench 4.0Claude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) by 3.552.549+3.5
ReasoningClaude Opus 5
- CritPtClaude Opus 5 by 1.427.729.1+1.4
- Humanity's Last Examtie54.754.9tie
FactsEven
- AA-Omniscience · Non-hallucinationClaude Opus 5 by 7.631.639.2+7.6
- AA-Omniscience · AccuracyClaude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) by 3.764.560.9+3.7
Images and chartsClaude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback)
- MMMU-ProClaude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) by 185.784.7+1
Long documentsClaude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback)
- AA-LCRClaude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) by 584.379.3+5
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.
- AA-OmniscienceClaude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) by 3.240.337.1+3.2
- AA Intelligencetie51.250.8tie
Questions people ask
Which is better, Claude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) or Claude Opus 5?
Claude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) wins three of the six areas where both have results: coding, images and charts and long documents. Claude Opus 5 wins reasoning. They are level on agents and facts.
Which is better for coding?
Claude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback). It wins the one coding test both models report.
Which is cheaper?
Claude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) costs $4.00 per million input tokens and $20.00 per million output tokens; Claude Opus 5 costs $5.00 and $25.00. That makes Claude Opus 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) about 20% cheaper for the same work.
How do you compare the two?
We use the 11 benchmark tests both models have published scores on. The verdict counts the 9 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.