DeepSeek-V4-Flash vs Qwen3.5 27B
Wins 6 of 7 areas
Coding · Agents · Reasoning · Math · Long documents · Following instructions
Wins 0 of 7 areas
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DeepSeek-V4-Flash is the stronger all-rounder.
Scores updated · 32 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 software70DeepSeek-V4-Flash7 of 7 tests
- ReasoningHard problems that need careful thinking30DeepSeek-V4-Flash3 of 3 tests
- MathCompetition and research-level math30DeepSeek-V4-Flash3 of 3 tests
- AgentsCarrying out multi-step tasks on its own21DeepSeek-V4-Flash2 of 4 tests · 1 tie
- Long documentsFinding answers in very long texts10DeepSeek-V4-Flash1 of 1 test
- Following instructionsDoing exactly what it is asked10DeepSeek-V4-Flash1 of 1 test
- FactsGetting facts right instead of making them up11Even1 each
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-Flash costs 84% 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 DeepSeek-V4-Flash pulls ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+19.7points ahead
- Research-level physics problemsCritPt+15.7points ahead
- Very hard expert questions across many subjectsHumanity's Last Exam+14.7points ahead
Where Qwen3.5 27B pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+10.2points ahead
- Finds the root cause of IT system incidentsAA IT-Bench SRE+4points ahead
Every test, side by side
All 32 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingDeepSeek-V4-Flash
- SciCodeDeepSeek-V4-Flash by 10.850.339.5+10.8
- LiveCodeBench v6DeepSeek-V4-Flash by 9.990.680.7+9.9
- LMArena · WebDevDeepSeek-V4-Flash by 73 rating points14301357+73 rating
- SWE-bench VerifiedDeepSeek-V4-Flash by 6.67972.4+6.6
- SWE-bench MultilingualDeepSeek-V4-Flash by 473.369.3+4
- Terminal-Bench HardDeepSeek-V4-Flash by 335.632.6+3
- SWE-bench ProDeepSeek-V4-Flash by 1.452.651.2+1.4
AgentsDeepSeek-V4-Flash
- GDPValDeepSeek-V4-Flash by 13.746.733+13.7
- BrowseCompDeepSeek-V4-Flash by 12.273.261+12.2
- AA IT-Bench SREQwen3.5 27B by 431.535.5+4
- MCP Atlastie6968.4tie
ReasoningDeepSeek-V4-Flash
- CritPtDeepSeek-V4-Flash by 15.716.60.9+15.7
- Humanity's Last ExamDeepSeek-V4-Flash by 14.738.623.9+14.7
- GPQA DiamondDeepSeek-V4-Flash by 590.885.8+5
FactsEven
- AA-Omniscience · AccuracyDeepSeek-V4-Flash by 19.740.420.7+19.7
- AA-Omniscience · Non-hallucinationQwen3.5 27B by 10.28.318.5+10.2
MathDeepSeek-V4-Flash
- HMMT Feb. 2026DeepSeek-V4-Flash by 13.794.881.1+13.7
- IMOAnswerBenchDeepSeek-V4-Flash by 8.588.479.9+8.5
- AIME 2026DeepSeek-V4-Flash by 4.195.891.7+4.1
Following instructionsDeepSeek-V4-Flash
- IFBenchDeepSeek-V4-Flash by 3.679.275.6+3.6
Other results11 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.
- Artificial Analysis Coding IndexDeepSeek-V4-Flash by 34.269.134.9+34.2
- AA-OmniscienceDeepSeek-V4-Flash by 29.7-14.3-44+29.7
- NL2RepoDeepSeek-V4-Flash by 26.954.227.3+26.9
- Terminal-Bench 2.0DeepSeek-V4-Flash by 15.356.941.6+15.3
- AA Agentic IndexQwen3.5 27B by 12.941.754.6+12.9
- AA IntelligenceDeepSeek-V4-Flash by 11.434.322.9+11.4
- WMT24++DeepSeek-V4-Flash by 7.985.577.6+7.9
- MMLU-ReduxQwen3.5 27B by 3.889.493.2+3.8
- MMLU-ProXDeepSeek-V4-Flash by 3.385.582.2+3.3
- τ²-Bench Telecom (AA run)DeepSeek-V4-Flash by 1.19593.9+1.1
- MMLU-Protie86.286.1tie
Questions people ask
Which is better, DeepSeek-V4-Flash or Qwen3.5 27B?
DeepSeek-V4-Flash wins six of the seven areas where both have results: coding, agents, reasoning, math, long documents and following instructions. Qwen3.5 27B wins none. They are level on facts.
Which is better for coding?
DeepSeek-V4-Flash. It wins 7 of the 7 coding tests both models report; Qwen3.5 27B wins none.
Which is cheaper?
DeepSeek-V4-Flash costs $0.14 per million input tokens and $0.28 per million output tokens; Qwen3.5 27B costs $0.30 and $2.40. That makes DeepSeek-V4-Flash about 84% cheaper for the same work.
How do you compare the two?
We use the 32 benchmark tests both models have published scores on. The verdict counts the 21 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 11 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.