Model comparison
DeepSeek-V3.1 vs Grok 4 Fast
DeepSeek-V3.1 is the stronger model overall, scoring 42.8 to 39.4 on the Noometry Index.
Last verified . 24 shared benchmarks.
DeepSeekSummary
- They share 24 benchmarks with published results for both. DeepSeek-V3.1 scores higher in 6 categories and Grok 4 Fast in 2 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in long context, where Grok 4 Fast leads 63.2 to 36.3.
- The biggest single-benchmark swing is Fiction.LiveBench: 52.8% for DeepSeek-V3.1 and 94.4% for Grok 4 Fast.
- DeepSeek-V3.1 has downloadable open weights; the other is API-only.
Side by side
| DeepSeek-V3.1 | Grok 4 Fast | |
|---|---|---|
| Provider | DeepSeek | xAI |
| Noometry Index | 42.8 | 39.4 |
| Released | 2025-08-21 | 2025-09-19 |
| Weights | Open | Proprietary |
| Context window | 164K | — |
| Max output | 8K | — |
| Input $ / M tokens | $0.25 | — |
| Output $ / M tokens | $0.95 | — |
| Results tracked | 27 | 30 |
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Category by category
Coding DeepSeek-V3.1 leads
DeepSeek-V3.1: 40.3 (#144), Grok 4 Fast: 32.5 (#271)
| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| WeirdML | 38.4% | 42.9% |
| LMArena Coding | 1417 | 1429 |
| LMArena WebDev | — | 1159 |
Agentic & Tool Use Not comparable
DeepSeek-V3.1: —, Grok 4 Fast: 29.5 (#86)
| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| τ²-bench Banking | — | 15.7% |
| Cybench | — | 30% |
| LMArena Search | — | 1171 |
Reasoning DeepSeek-V3.1 leads
DeepSeek-V3.1: 27.9 (#110), Grok 4 Fast: 22.2 (#201)
| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| Kagi LLM Benchmark | 53.2% | 66.1% |
| LMArena Hard Prompts | 1417 | 1412 |
| DTBench | 82.7% | 82.7% |
| Epoch Capabilities Index | 139.92 | 144.2 |
| ForecastBench | 58 | 60.5 |
| ARC-AGI-2 | — | 5.3% |
| SimpleBench | 40% | — |
| ARC-AGI-1 | — | 48.5% |
| LMCA | 24.3% | — |
Math Too close to call
DeepSeek-V3.1: 38.9 (#122), Grok 4 Fast: 38.9 (#123)
| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| LMArena Math | 1420 | 1419 |
Knowledge DeepSeek-V3.1 leads
DeepSeek-V3.1: 43.7 (#90), Grok 4 Fast: 32.0 (#214)
| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| Vectara Hallucination Rate | 5.5% | 19.7% |
| LMArena Expert | 1405 | 1411 |
Multilingual Too close to call
DeepSeek-V3.1: 51.6 (#106), Grok 4 Fast: 51.3 (#111)
| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| LMArena Non-English | 1400 | 1396 |
| LMArena Chinese | 1469 | 1457 |
| LMArena French | 1447 | 1431 |
| LMArena German | 1411 | 1383 |
| LMArena Japanese | 1378 | 1352 |
| LMArena Korean | 1337 | 1357 |
| LMArena Russian | 1405 | 1389 |
| LMArena Spanish | 1431 | 1415 |
Instruction Following Too close to call
DeepSeek-V3.1: 73.9 (#110), Grok 4 Fast: 73.2 (#121)
| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| LMArena Instruction Following | 1400 | 1387 |
Long Context Grok 4 Fast leads
DeepSeek-V3.1: 36.3 (#232), Grok 4 Fast: 63.2 (#3)
| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| Fiction.LiveBench | 52.8% | 94.4% |
| LMArena Longer Query | 1422 | 1415 |
Writing & Preference Too close to call
DeepSeek-V3.1: 60.3 (#98), Grok 4 Fast: 60.0 (#102)
| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| LMArena Text | 1420 | 1407 |
| LMArena Creative Writing | 1401 | 1387 |
| LMArena Multi-Turn | 1408 | 1414 |
| EQ-Bench Creative Writing | 1436 | — |
Frequently asked questions
Is DeepSeek-V3.1 better than Grok 4 Fast?
DeepSeek-V3.1 is the stronger model overall, scoring 42.8 to 39.4 on the Noometry Index.
Is DeepSeek-V3.1 or Grok 4 Fast better for coding?
DeepSeek-V3.1 scores higher on coding benchmarks: 40.3 versus 32.5 in the Noometry coding category.
How many benchmarks do DeepSeek-V3.1 and Grok 4 Fast share?
24 benchmarks have published results for both models. DeepSeek-V3.1 has 27 scored results on Noometry and Grok 4 Fast has 30.