Claude Opus 5.5 vs Step 5 Preview
Wins 4 of 6 areas
Coding · Agents · Reasoning · Images and charts
Wins 1 of 6 areas
Long documents
Claude Opus 5.5 is the stronger all-rounder.Step 5 Preview is cheaper and better at long documents.
Both rank among the ten best models we track in long documents.
Scores updated · 14 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 software20Claude Opus 5.52 of 2 tests
- ReasoningHard problems that need careful thinking20Claude Opus 5.52 of 2 tests
- Images and chartsUnderstanding pictures, charts and video20Claude Opus 5.52 of 2 tests
- AgentsCarrying out multi-step tasks on its own21Claude Opus 5.52 of 3 tests
- Long documentsFinding answers in very long texts01Step 5 Preview1 of 1 test
- FactsGetting facts right instead of making them up11Even1 each
Long documents rests on a single test.
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.
Step 5 Preview costs 85% 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
- Complex command-line tasks across many fieldsTerminal-Bench 4.0+26.3points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+24.7points ahead
- Very hard expert questions across many subjectsHumanity's Last Exam+14.9points ahead
Where Step 5 Preview pulls ahead
- Finds the root cause of IT system incidentsAA IT-Bench SRE+17.4points ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+15.6points ahead
- Reasons across sets of long documentsAA-LCR+3.6points ahead
Every test, side by side
All 14 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Opus 5.5
- LMArena · WebDevClaude Opus 5.5 by 239 rating points18101571+239 rating
- SciCodeClaude Opus 5.5 by 866.958.9+8
AgentsClaude Opus 5.5
- Terminal-Bench 4.0Claude Opus 5.5 by 26.359.633.3+26.3
- AA IT-Bench SREStep 5 Preview by 17.438.255.6+17.4
- GDPValClaude Opus 5.5 by 1468.354.3+14
ReasoningClaude Opus 5.5
- Humanity's Last ExamClaude Opus 5.5 by 14.961.446.5+14.9
- CritPtClaude Opus 5.5 by 10.831.720.9+10.8
FactsEven
- AA-Omniscience · AccuracyClaude Opus 5.5 by 24.766.241.5+24.7
- AA-Omniscience · Non-hallucinationStep 5 Preview by 15.641.457+15.6
Images and chartsClaude Opus 5.5
- MMMU-ProClaude Opus 5.5 by 11.387.776.4+11.3
- LMArena · VisionClaude Opus 5.5 by 56 rating points13211265+56 rating
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 by 3046.416.4+30
- AA IntelligenceClaude Opus 5.5 by 13.957.643.7+13.9
Questions people ask
Which is better, Claude Opus 5.5 or Step 5 Preview?
Claude Opus 5.5 wins four of the six areas where both have results: coding, agents, reasoning and images and charts. Step 5 Preview wins long documents, and costs 85% less. They are level on facts.
Which is better for coding?
Claude Opus 5.5. It wins 2 of the 2 coding tests both models report; Step 5 Preview wins none.
Which is cheaper?
Claude Opus 5.5 costs $4.00 per million input tokens and $20.00 per million output tokens; Step 5 Preview costs $1.00 and $2.70. That makes Step 5 Preview about 85% cheaper for the same work.
How do you compare the two?
We use the 14 benchmark tests both models have published scores on. The verdict counts the 12 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.