Model comparison
DeepSeek V4 Flash vs Mistral Medium 3.5 128B
Head-to-head evidence from 2 shared benchmark results across 2 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: DeepSeek V4 Flash #68 (Estimated); Mistral Medium 3.5 128B unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. DeepSeek V4 Flash and Mistral Medium 3.5 128B share 2 comparable benchmark results. 1 of 8 categories are comparable. 20 results are unique to DeepSeek V4 Flash; 23 to Mistral Medium 3.5 128B.
Updated July 27, 2026- Shared results
- 2
- DeepSeek V4 Flash only
- 20
- Mistral Medium 3.5 128B only
- 23
- Comparable categories
- 1 / 8
Treat this as a split decision. DeepSeek V4 Flash makes more sense if you want the cheaper token bill or you need the larger 1M context window; Mistral Medium 3.5 128B is the better fit if coding is the priority or you want the stronger reasoning-first profile.
Confidence note. This is a partial-evidence comparison with 2 shared benchmark results across 2 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
DeepSeek V4 Flash and Mistral Medium 3.5 128B finish on the same BenchAlign overall score, so this is less about a single winner and more about where the edge shows up. The BenchAlign headline says tie; the benchmark table is where the real choice happens.
Mistral Medium 3.5 128B is also the more expensive model on tokens at $1.50 input / $7.50 output per 1M tokens, versus $0.14 input / $0.28 output per 1M tokens for DeepSeek V4 Flash. That is roughly 26.8x on output cost alone. Mistral Medium 3.5 128B is the reasoning model in the pair, while DeepSeek V4 Flash 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 gives you the larger context window at 1M, compared with 256K for Mistral Medium 3.5 128B.
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 | Δ | Mistral Medium 3.5 128B |
|---|---|---|---|
| Coding | DeepSeek V4 Flash64.2 | Margin→ 13.4 | Mistral Medium 3.5 128B77.6 |
| Agentic | DeepSeek V4 Flash49.1 | MarginNo overlap | Mistral Medium 3.5 128BNot measured |
| Knowledge | DeepSeek V4 Flash38.8 | MarginNo overlap | Mistral Medium 3.5 128BNot measured |
| Math | DeepSeek V4 Flash40.8 | MarginNo overlap | Mistral Medium 3.5 128BNot measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
SWE-bench Verified
CodingA 73.7%B 77.6%Winner: Mistral Medium 3.5 128BΔ 3.9SWE-bench Verified: DeepSeek V4 Flash scored 73.7%; Mistral Medium 3.5 128B scored 77.6%. Mistral Medium 3.5 128B wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | DeepSeek V4 Flash | Mistral Medium 3.5 128B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | DeepSeek V4 Flash$0.14 input / $0.28 output | Mistral Medium 3.5 128B$1.5 input / $7.5 output | DeepSeek V4 Flash has the lower combined listed price. |
| Generation speedtokens per second | DeepSeek V4 FlashNot available | Mistral Medium 3.5 128BNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | DeepSeek V4 FlashNot available | Mistral Medium 3.5 128BNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | DeepSeek V4 Flash1M | Mistral Medium 3.5 128B256K | DeepSeek V4 Flash lists the larger context window. |
Benchmark Deep Dive
Agentic15 benchmarks
| Benchmark | DeepSeek V4 Flash | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 49.1% | — | Not comparable |
| MCP AtlasSource | 64% | — | Not comparable |
| ToolathlonSource | 40.7% | — | Not comparable |
| Claw-EvalSource | 57.8% | — | Not comparable |
| Gert LabsSource | 54.35% | 39.10% | DeepSeek V4 Flash leads |
| τ³-bench resultsSource | — | 91.4% | Not comparable |
| AA Agentic IndexSource | — | 19.0% | Not comparable |
| τ²-bench resultsSource | — | 94.2% | Not comparable |
| GDPval-AASource | — | 21.6% | Not comparable |
| GDPval-AASource | — | 933 | Not comparable |
| AA EnterpriseOps-GymSource | — | 33.7% | Not comparable |
| AA Harvey LABSource | — | 69.1% | Not comparable |
| terminalBenchHardSource | — | 33.3% | Not comparable |
| AA BriefcaseSource | — | 516 | Not comparable |
| AA Tau3 BankingSource | — | 14.4% | Not comparable |
CodingMistral Medium 3.5 128B wins6 benchmarks
| Benchmark | DeepSeek V4 Flash | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 73.7% | 77.6% | Mistral Medium 3.5 128B leads |
| SWE-bench ProSource | 49.1% | — | Not comparable |
| SWE MultilingualSource | 69.7% | — | Not comparable |
| Terminal-Bench 2.0Source | 49.1% | — | Not comparable |
| AA Coding IndexSource | — | 46.9% | Not comparable |
| AA-SciCodeSource | — | 39.6% | Not comparable |
Reasoning4 benchmarks
Knowledge13 benchmarks
| Benchmark | DeepSeek V4 Flash | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| MMLU-ProSource | 83% | — | Not comparable |
| SimpleQASource | 23.1% | — | Not comparable |
| Chinese-SimpleQASource | 71.5% | — | Not comparable |
| GPQASource | 71.2% | — | Not comparable |
| GPQA-DSource | 71.2% | — | Not comparable |
| HLESource | 8.1% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 29.9% | Not comparable |
| AA-GPQA DiamondSource | — | 74.8% | Not comparable |
| AA-HLESource | — | 12.8% | Not comparable |
| AA-Omniscience IndexSource | — | -36.3% | Not comparable |
| AA-Omniscience AccuracySource | — | 25.1% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 82.0% | Not comparable |
| AA Openness IndexSource | — | 33.3% | Not comparable |
Math4 benchmarks
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | DeepSeek V4 Flash | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 68.8% | Not comparable |
Frequently Asked Questions (2)
Which is better, DeepSeek V4 Flash or Mistral Medium 3.5 128B?
DeepSeek V4 Flash and Mistral Medium 3.5 128B are tied on the BenchAlign overall score, so the right pick depends on which category matters most for your use case.
Which is better for coding, DeepSeek V4 Flash or Mistral Medium 3.5 128B?
Mistral Medium 3.5 128B has the edge for coding in this comparison, averaging 77.6 versus 64.2. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
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