Claude Opus 4.8 vs DeepSeek-V4-Flash
Wins 5 of 7 areas
Coding · Agents · Reasoning · Facts · Math
Wins 1 of 7 areas
Long documents
Claude Opus 4.8 is the stronger all-rounder.DeepSeek-V4-Flash is cheaper and better at long documents.
Scores updated · 56 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 software90Claude Opus 4.89 of 9 tests
- ReasoningHard problems that need careful thinking60Claude Opus 4.86 of 6 tests
- MathCompetition and research-level math41Claude Opus 4.84 of 6 tests · 1 tie
- FactsGetting facts right instead of making them up30Claude Opus 4.83 of 3 tests
- AgentsCarrying out multi-step tasks on its own31Claude Opus 4.83 of 5 tests · 1 tie
- Long documentsFinding answers in very long texts01DeepSeek-V4-Flash1 of 1 test
- Following instructionsDoing exactly what it is asked11Even1 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.
DeepSeek-V4-Flash costs 94% 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 4.8 pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+52.4points ahead
- Extremely hard research-level math problemsFrontierMath Tier 4+31.7points ahead
- Hard command-line tasks in a real terminalTerminal-Bench Hard+22.7points ahead
Where DeepSeek-V4-Flash pulls ahead
- Follows unfamiliar, precisely checkable instructionsIFBench+17points ahead
- Customer-service tasks in a simulated bankτ-Bench V3 · Banking+5.2points ahead
- Olympiad math problems with short answersIMOAnswerBench+4.9points ahead
Every test, side by side
All 56 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Opus 4.8
- Terminal-Bench HardClaude Opus 4.8 by 22.758.335.6+22.7
- SWE-bench ProClaude Opus 4.8 by 16.669.252.6+16.6
- LMArena · WebDevClaude Opus 4.8 by 126 rating points15561430+126 rating
- SWE-bench MultilingualClaude Opus 4.8 by 11.184.473.3+11.1
- SWE-bench VerifiedClaude Opus 4.8 by 9.688.679+9.6
- LiveBench · CodingClaude Opus 4.8 by 6.881.875+6.8
- Terminal-Bench 2.1Claude Opus 4.8 by 5.984.678.7+5.9
- SciCodeClaude Opus 4.8 by 4.154.450.3+4.1
- LiveBench · Agentic CodingClaude Opus 4.8 by 3.750.546.8+3.7
AgentsClaude Opus 4.8
- MCP AtlasClaude Opus 4.8 by 13.282.269+13.2
- BrowseCompClaude Opus 4.8 by 11.184.373.2+11.1
- Terminal-Bench 4.0Claude Opus 4.8 by 9.621.712.1+9.6
- τ-Bench V3 · BankingDeepSeek-V4-Flash by 5.234.239.4+5.2
- GDPValtie47.846.9tie
ReasoningClaude Opus 4.8
- SimpleBenchClaude Opus 4.8 by 18.564.846.3+18.5
- ARC-AGI-2Claude Opus 4.8 by 10.772.161.4+10.7
- Humanity's Last ExamClaude Opus 4.8 by 10.148.738.6+10.1
- CritPtClaude Opus 4.8 by 4.320.916.6+4.3
- LiveBench · ReasoningClaude Opus 4.8 by 2.689.286.6+2.6
- GPQA DiamondClaude Opus 4.8 by 1.29290.8+1.2
FactsClaude Opus 4.8
- AA-Omniscience · Non-hallucinationClaude Opus 4.8 by 52.460.78.3+52.4
- SimpleQA VerifiedClaude Opus 4.8 by 18.95334.1+18.9
- AA-Omniscience · AccuracyClaude Opus 4.8 by 8.448.840.4+8.4
MathClaude Opus 4.8
- FrontierMath Tier 4Claude Opus 4.8 by 31.756.124.4+31.7
- FrontierMath Tiers 1-3 (v2)Claude Opus 4.8 by 22.58057.5+22.5
- LiveBench · MathematicsClaude Opus 4.8 by 7.594.386.8+7.5
- IMOAnswerBenchDeepSeek-V4-Flash by 4.983.588.4+4.9
- AIME 2026Claude Opus 4.8 by 4.210095.8+4.2
- HMMT Feb. 2026tie95.594.8tie
Following instructionsEven
- IFBenchDeepSeek-V4-Flash by 1762.279.2+17
- LiveBench · Instruction FollowingClaude Opus 4.8 by 6.57265.5+6.5
Other results24 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.
- GDPval-AA (Elo)Claude Opus 4.8 by 495 rating points18901395+495 rating
- AA-OmniscienceClaude Opus 4.8 by 43.128.8-14.3+43.1
- GDPval-AA v2Claude Opus 4.8 by 404 rating points15931189+404 rating
- Terminal-Bench 2.0Claude Opus 4.8 by 17.774.656.9+17.7
- NL2RepoClaude Opus 4.8 by 15.569.754.2+15.5
- livebench_data_analysisDeepSeek-V4-Flash by 13.36679.3+13.3
- HLE (with tools)Claude Opus 4.8 by 12.857.945.1+12.8
- HLE (wo / w tools)Claude Opus 4.8 by 12.857.945.1+12.8
- DSBench-HardClaude Opus 4.8 by 12.171.759.6+12.1
- ToolathlonDeepSeek-V4-Flash by 10.459.970.3+10.4
- Toolathlon VerifiedClaude Opus 4.8 by 9.679.970.3+9.6
- AA IntelligenceClaude Opus 4.8 by 7.541.834.3+7.5
- JobBenchClaude Opus 4.8 by 7.148.441.3+7.1
- Artificial Analysis Coding IndexClaude Opus 4.8 by 5.274.369.1+5.2
- DeepSWE 1.1Claude Opus 4.8 by 4.65954.4+4.6
- DeepSWEClaude Opus 4.8 by 3.65854.4+3.6
- ARC-AGI-1Claude Opus 4.8 by 3.592.589+3.5
- DSBench-FullStackClaude Opus 4.8 by 2.971.668.7+2.9
- AutomationBench PublicClaude Opus 4.8 by 2.127.225.1+2.1
- CyberGymClaude Opus 4.8 by 2.178.876.7+2.1
- AA Agentic Indextie42.641.7tie
- τ²-Bench Telecom (AA run)tie94.495tie
- Agents' Last Examtie25.725.2tie
- livebench_languagetie79.779.2tie
Questions people ask
Which is better, Claude Opus 4.8 or DeepSeek-V4-Flash?
Claude Opus 4.8 wins five of the seven areas where both have results: coding, agents, reasoning, facts and math. DeepSeek-V4-Flash wins long documents, and costs 94% less. They are level on following instructions.
Which is better for coding?
Claude Opus 4.8. It wins 9 of the 9 coding tests both models report; DeepSeek-V4-Flash wins none.
Which is cheaper?
Claude Opus 4.8 costs $5.00 per million input tokens and $25.00 per million output tokens; DeepSeek-V4-Flash costs $0.44 and $1.32. That makes DeepSeek-V4-Flash about 94% cheaper for the same work.
How do you compare the two?
We use the 56 benchmark tests both models have published scores on. The verdict counts the 32 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 24 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.