Claude Opus 5.5 vs DeepSeek-V4-Pro
Wins 7 of 7 areas
Coding · Agents · Reasoning · Facts · Math · Long documents · Following instructions
Wins 0 of 7 areas
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Claude Opus 5.5 is the stronger all-rounder.DeepSeek-V4-Pro is cheaper.
Scores updated · 35 tests both models report · How we compare
Where each one wins
Tests won in each of the seven 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 software60Claude Opus 5.56 of 6 tests
- ReasoningHard problems that need careful thinking40Claude Opus 5.54 of 4 tests
- MathCompetition and research-level math30Claude Opus 5.53 of 3 tests
- FactsGetting facts right instead of making them up31Claude Opus 5.53 of 4 tests
- AgentsCarrying out multi-step tasks on its own20Claude Opus 5.52 of 3 tests · 1 tie
- Long documentsFinding answers in very long texts10Claude Opus 5.51 of 1 test
- Following instructionsDoing exactly what it is asked10Claude Opus 5.51 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.
DeepSeek-V4-Pro costs 95% 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 Opus 5.5 pulls ahead
- Extremely hard research-level math problemsFrontierMath Tier 4+92.6points ahead
- Unpublished advanced math problemsFrontierMath Tiers 1-3 (v2)+45.9points ahead
- Complex command-line tasks across many fieldsTerminal-Bench 4.0+45points ahead
Where DeepSeek-V4-Pro pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 35 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Opus 5.5
- SWE-bench ProClaude Opus 5.5 by 34.589.955.4+34.5
- LMArena · WebDevClaude Opus 5.5 by 343 rating points18071464+343 rating
- LiveBench · Agentic CodingClaude Opus 5.5 by 29.171.742.6+29.1
- LiveBench · CodingClaude Opus 5.5 by 19.389.370+19.3
- SWE-bench MultilingualClaude Opus 5.5 by 17.793.976.2+17.7
- SciCodeClaude Opus 5.5 by 16.166.950.8+16.1
AgentsClaude Opus 5.5
- Terminal-Bench 4.0Claude Opus 5.5 by 4559.614.6+45
- GDPValClaude Opus 5.5 by 35.568.332.8+35.5
- AA IT-Bench SREtie38.238.3tie
ReasoningClaude Opus 5.5
- SimpleBenchClaude Opus 5.5 by 37.588.450.9+37.5
- Humanity's Last ExamClaude Opus 5.5 by 23.961.437.5+23.9
- CritPtClaude Opus 5.5 by 18.831.712.9+18.8
- LiveBench · ReasoningClaude Opus 5.5 by 9.592.282.7+9.5
FactsClaude Opus 5.5
- AA-Omniscience · Non-hallucinationClaude Opus 5.5 by 35.541.45.9+35.5
- SimpleQA VerifiedClaude Opus 5.5 by 2672.246.2+26
- AA-Omniscience · AccuracyClaude Opus 5.5 by 23.266.243+23.2
- Vectara HHEM hallucination ratelower is betterDeepSeek-V4-Pro by 1.39.98.6+1.3
MathClaude Opus 5.5
- FrontierMath Tier 4Claude Opus 5.5 by 92.6952.4+92.6
- FrontierMath Tiers 1-3 (v2)Claude Opus 5.5 by 45.991.245.3+45.9
- LiveBench · MathematicsClaude Opus 5.5 by 6.497.190.7+6.4
Following instructionsClaude Opus 5.5
- LiveBench · Instruction FollowingClaude Opus 5.5 by 3.365.762.4+3.3
Other results13 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 57.146.4-10.7+57.1
- Terminal-Bench 4.0Claude Opus 5.5 by 5466.412.4+54
- Program BenchClaude Opus 5.5 by 43.491.247.8+43.4
- AA IntelligenceClaude Opus 5.5 by 27.257.630.4+27.2
- GDPval-AA (Elo)Claude Opus 5.5 by 266 rating points18201554+266 rating
- Toolathlon VerifiedClaude Opus 5.5 by 21.977.855.9+21.9
- HiL-Bench (Tools-allowed)Claude Opus 5.5 by 20.55938.5+20.5
- livebench_languageClaude Opus 5.5 by 8.286.378.1+8.2
- HLE (with tools)Claude Opus 5.5 by 7.767.760+7.7
- livebench_data_analysisClaude Opus 5.5 by 5.880.374.5+5.8
- vectara_avg_summary_lengthClaude Opus 5.5 by 38.3 rating points192.1153.8+38.3 rating
- vectara_answer_rateClaude Opus 5.5 by 2.599.797.2+2.5
- vectara_factual_consistencyDeepSeek-V4-Pro by 1.390.191.4+1.3
Questions people ask
Which is better, Claude Opus 5.5 or DeepSeek-V4-Pro?
Claude Opus 5.5 wins all seven areas where both have results: coding, agents, reasoning, facts, math, long documents and following instructions. DeepSeek-V4-Pro wins none, but costs 95% less.
Which is better for coding?
Claude Opus 5.5. It wins 6 of the 6 coding tests both models report; DeepSeek-V4-Pro wins none.
Which is cheaper?
Claude Opus 5.5 costs $4.00 per million input tokens and $20.00 per million output tokens; DeepSeek-V4-Pro costs $0.43 and $0.87. That makes DeepSeek-V4-Pro about 95% cheaper for the same work.
How do you compare the two?
We use the 35 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 13 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.