Model comparison
DeepSeek V4 Flash (High) vs Qwen3.5 397B
Head-to-head evidence from 25 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: DeepSeek V4 Flash (High) #92 (Estimated); Qwen3.5 397B #71 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. DeepSeek V4 Flash (High) and Qwen3.5 397B share 25 comparable benchmark results. 4 of 8 categories are comparable. 13 results are unique to DeepSeek V4 Flash (High); 30 to Qwen3.5 397B.
Updated July 23, 2026- Shared results
- 25
- DeepSeek V4 Flash (High) only
- 13
- Qwen3.5 397B only
- 30
- Comparable categories
- 4 / 8
Pick Qwen3.5 397B if you want the stronger benchmark profile. DeepSeek V4 Flash (High) only becomes the better choice if coding is the priority or you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 25 shared benchmark results across 6 evidence categories; 4 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
Qwen3.5 397B is clearly ahead on the BenchAlign aggregate, 57.01 to 53.95. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Qwen3.5 397B's sharpest advantage is in knowledge, where it averages 56.6 against 52.1. The single biggest benchmark swing on the page is BrowseComp, 53.5% to 62%. DeepSeek V4 Flash (High) does hit back in coding, so the answer changes if that is the part of the workload you care about most.
Qwen3.5 397B is also the more expensive model on tokens at $0.60 input / $3.60 output per 1M tokens, versus $0.14 input / $0.28 output per 1M tokens for DeepSeek V4 Flash (High). That is roughly 12.9x on output cost alone. DeepSeek V4 Flash (High) is the reasoning model in the pair, while Qwen3.5 397B is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. DeepSeek V4 Flash (High) gives you the larger context window at 1M, compared with 128K for Qwen3.5 397B.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | DeepSeek V4 Flash (High) | Δ | Qwen3.5 397B |
|---|---|---|---|
| Knowledge | DeepSeek V4 Flash (High)52.1 | Margin→ 4.5 | Qwen3.5 397B56.6 |
| Coding | DeepSeek V4 Flash (High)68.5 | Margin← 2.0 | Qwen3.5 397B66.5 |
| Math | DeepSeek V4 Flash (High)91.9 | Margin← 1.3 | Qwen3.5 397B90.6 |
| Agentic | DeepSeek V4 Flash (High)55.3 | Margin→ 1.2 | Qwen3.5 397B56.5 |
| Reasoning | DeepSeek V4 Flash (High)Not measured | MarginNo overlap | Qwen3.5 397B63.2 |
| Multilingual | DeepSeek V4 Flash (High)Not measured | MarginNo overlap | Qwen3.5 397B84.7 |
| Multimodal | DeepSeek V4 Flash (High)Not measured | MarginNo overlap | Qwen3.5 397B79.6 |
| Inst. Following | DeepSeek V4 Flash (High)Not measured | MarginNo overlap | Qwen3.5 397B92.6 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
BrowseComp
AgenticA 53.5%B 62%Winner: Qwen3.5 397BΔ 8.5BrowseComp: DeepSeek V4 Flash (High) scored 53.5%; Qwen3.5 397B scored 62%. Qwen3.5 397B wins this benchmark. - Source ↗
Terminal-Bench 2.0
AgenticA 56.6%B 52.5%Winner: DeepSeek V4 Flash (High)Δ 4.1Terminal-Bench 2.0: DeepSeek V4 Flash (High) scored 56.6%; Qwen3.5 397B scored 52.5%. DeepSeek V4 Flash (High) wins this benchmark. - Source ↗
HMMT Feb 2026
MathA 91.9%B 87.9%Winner: DeepSeek V4 Flash (High)Δ 4HMMT Feb 2026: DeepSeek V4 Flash (High) scored 91.9%; Qwen3.5 397B scored 87.9%. DeepSeek V4 Flash (High) wins this benchmark. - Source ↗
SWE-bench Verified
CodingA 78.6%B 76.2%Winner: DeepSeek V4 Flash (High)Δ 2.4SWE-bench Verified: DeepSeek V4 Flash (High) scored 78.6%; Qwen3.5 397B scored 76.2%. DeepSeek V4 Flash (High) wins this benchmark. - Source ↗
SWE-bench Pro
CodingA 52.3%B 50.9%Winner: DeepSeek V4 Flash (High)Δ 1.4SWE-bench Pro: DeepSeek V4 Flash (High) scored 52.3%; Qwen3.5 397B scored 50.9%. DeepSeek V4 Flash (High) wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | DeepSeek V4 Flash (High) | Qwen3.5 397B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | DeepSeek V4 Flash (High)$0.14 input / $0.28 output | Qwen3.5 397B$0.6 input / $3.6 output | DeepSeek V4 Flash (High) has the lower combined listed price. |
| Generation speedtokens per second | DeepSeek V4 Flash (High)Not available | Qwen3.5 397B96 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | DeepSeek V4 Flash (High)Not available | Qwen3.5 397B2.44 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | DeepSeek V4 Flash (High)1M | Qwen3.5 397B128K | DeepSeek V4 Flash (High) lists the larger context window. |
Benchmark Deep Dive
AgenticQwen3.5 397B wins19 benchmarks
| Benchmark | DeepSeek V4 Flash (High) | Qwen3.5 397B | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 56.6% | 52.5% | DeepSeek V4 Flash (High) leads |
| BrowseCompSource | 53.5% | 62% | Qwen3.5 397B leads |
| HLE w/ toolsSource | 40.3% | — | Not comparable |
| MCP AtlasSource | 67.4% | 46.1% | DeepSeek V4 Flash (High) leads |
| ToolathlonSource | 43.5% | 36.3% | DeepSeek V4 Flash (High) leads |
| τ²-bench resultsSource | 95.6% | 95.6% | Tie |
| AA Agentic IndexSource | 28.2% | 19.9% | DeepSeek V4 Flash (High) leads |
| GDPval-AASource | 32.4% | 23.1% | DeepSeek V4 Flash (High) leads |
| GDPval-AASource | 1147 | 962 | DeepSeek V4 Flash (High) leads |
| Claw-EvalSource | — | 56.8% | Not comparable |
| QwenClawBenchSource | — | 51.8% | Not comparable |
| τ³-bench resultsSource | — | 68.4% | Not comparable |
| VITA-BenchSource | — | 43.7% | Not comparable |
| DeepPlanningSource | — | 37.6% | Not comparable |
| MCP-TasksSource | — | 74.2% | Not comparable |
| WideResearchSource | — | 74.0% | Not comparable |
| Gert LabsSource | — | 46.76% | Not comparable |
| ResearchClawBenchSource | — | 14.2% | Not comparable |
| APEX-Agents-AASource | — | 15.3% | Not comparable |
CodingDeepSeek V4 Flash (High) wins8 benchmarks
| Benchmark | DeepSeek V4 Flash (High) | Qwen3.5 397B | Result |
|---|---|---|---|
| CodeforcesSource | 2816.0 | — | Not comparable |
| SWE-bench VerifiedSource | 78.6% | 76.2% | DeepSeek V4 Flash (High) leads |
| SWE-bench ProSource | 52.3% | 50.9% | DeepSeek V4 Flash (High) leads |
| SWE MultilingualSource | 70.2% | — | Not comparable |
| Terminal-Bench 2.0Source | 56.6% | — | Not comparable |
| AA-SciCodeSource | 42.0% | 42.0% | Tie |
| AA Coding IndexSource | 52.0% | 48.2% | DeepSeek V4 Flash (High) leads |
| LiveCodeBench v6Source | — | 83.6% | Not comparable |
Reasoning6 benchmarks
KnowledgeQwen3.5 397B wins15 benchmarks
| Benchmark | DeepSeek V4 Flash (High) | Qwen3.5 397B | Result |
|---|---|---|---|
| MMLU-ProSource | 86.4% | 87.8% | Qwen3.5 397B leads |
| SimpleQASource | 28.9% | — | Not comparable |
| Chinese-SimpleQASource | 73.2% | — | Not comparable |
| GPQASource | 87.4% | 88.4% | Qwen3.5 397B leads |
| GPQA-DSource | 87.4% | — | Not comparable |
| HLESource | 29.4% | 28.7% | DeepSeek V4 Flash (High) leads |
| Artificial Analysis Intelligence IndexSource | 37.5% | 33.7% | DeepSeek V4 Flash (High) leads |
| AA-GPQA DiamondSource | 86.7% | 89.3% | Qwen3.5 397B leads |
| AA-HLESource | 27.8% | 27.3% | DeepSeek V4 Flash (High) leads |
| AA-Omniscience IndexSource | -22.3% | -29.8% | DeepSeek V4 Flash (High) leads |
| AA-Omniscience AccuracySource | 35.5% | 31.4% | DeepSeek V4 Flash (High) leads |
| AA-Omniscience Hallucination RateSource | 89.7% | 89.1% | Qwen3.5 397B leads |
| SuperGPQASource | — | 70.4% | Not comparable |
| MMLU-ReduxSource | — | 94.9% | Not comparable |
| C-EvalSource | — | 93% | Not comparable |
MathDeepSeek V4 Flash (High) wins8 benchmarks
| Benchmark | DeepSeek V4 Flash (High) | Qwen3.5 397B | Result |
|---|---|---|---|
| HMMT Feb 2026Source | 91.9% | 87.9% | DeepSeek V4 Flash (High) leads |
| IMOAnswerBenchSource | 85.1% | — | Not comparable |
| ApexSource | 19.1% | — | Not comparable |
| Apex ShortlistSource | 72.1% | — | Not comparable |
| AIME26Source | — | 93.3% | Not comparable |
| HMMT Feb 2025Source | — | 94.8% | Not comparable |
| HMMT Nov 2025Source | — | 92.7% | Not comparable |
| MMAnswerBenchSource | — | 80.9% | Not comparable |
Multilingual2 benchmarks
Multimodal8 benchmarks
| Benchmark | DeepSeek V4 Flash (High) | Qwen3.5 397B | Result |
|---|---|---|---|
| Design Arena WebsiteSource | 1238 | — | Not comparable |
| MMMU-ProSource | — | 79% | Not comparable |
| MathVisionSource | — | 88.6% | Not comparable |
| CharXivSource | — | 80.8% | Not comparable |
| VideoMMMUSource | — | 84.7% | Not comparable |
| ScreenSpot ProSource | — | 65.6% | Not comparable |
| V*Source | — | 95.8% | Not comparable |
| AA-MMMU-ProSource | — | 77.3% | Not comparable |
Frequently Asked Questions (5)
Which is better, DeepSeek V4 Flash (High) or Qwen3.5 397B?
Qwen3.5 397B is ahead on BenchLM's BenchAlign leaderboard, 57.01 to 53.95. The biggest single separator in this matchup is BrowseComp, where the scores are 53.5% and 62%.
Which is better for knowledge tasks, DeepSeek V4 Flash (High) or Qwen3.5 397B?
Qwen3.5 397B has the edge for knowledge tasks in this comparison, averaging 56.6 versus 52.1. Inside this category, AA-Omniscience Index is the benchmark that creates the most daylight between them.
Which is better for coding, DeepSeek V4 Flash (High) or Qwen3.5 397B?
DeepSeek V4 Flash (High) has the edge for coding in this comparison, averaging 68.5 versus 66.5. Inside this category, AA Coding Index is the benchmark that creates the most daylight between them.
Which is better for math, DeepSeek V4 Flash (High) or Qwen3.5 397B?
DeepSeek V4 Flash (High) has the edge for math in this comparison, averaging 91.9 versus 90.6. Inside this category, HMMT Feb 2026 is the benchmark that creates the most daylight between them.
Which is better for agentic tasks, DeepSeek V4 Flash (High) or Qwen3.5 397B?
Qwen3.5 397B has the edge for agentic tasks in this comparison, averaging 56.5 versus 55.3. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.
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