Model comparison
Grok 3 vs Grok 4.1 Fast
Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 39.9 on the Noometry Index.
Last verified . 20 shared benchmarks.
Summary
- They share 20 benchmarks with published results for both. Grok 3 scores higher in 5 categories and Grok 4.1 Fast in 4 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.1 Fast leads 43.4 to 13.7.
- The biggest single-benchmark swing is SimpleBench: 36.1% for Grok 3 and 56% for Grok 4.1 Fast.
Side by side
| Grok 3 | Grok 4.1 Fast | |
|---|---|---|
| Provider | xAI | xAI |
| Noometry Index | 39.9 | 41.4 |
| Released | 2025-04-09 | 2025-06-27 |
| Weights | Proprietary | Proprietary |
| Context window | — | 128K |
| Max output | — | 30K |
| Input $ / M tokens | — | $0.20 |
| Output $ / M tokens | — | $0.50 |
| Results tracked | 40 | 32 |
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Category by category
Coding Grok 3 leads
Grok 3: 41.9 (#115), Grok 4.1 Fast: 34.1 (#245)
| Benchmark | Grok 3 | Grok 4.1 Fast |
|---|---|---|
| LMArena Coding | 1432 | 1411 |
| Aider Polyglot | 53.3% | — |
| LMArena WebDev | — | 1242 |
| WeirdML | 37.2% | — |
| ALE-Bench | — | 394.93 |
Agentic & Tool Use Grok 4.1 Fast leads
Grok 3: 30.5 (#76), Grok 4.1 Fast: 36.3 (#39)
| Benchmark | Grok 3 | Grok 4.1 Fast |
|---|---|---|
| Berkeley Function Calling Leaderboard | — | 69.6% |
| τ²-bench Banking | — | 13.1% |
| BALROG | 29.5% | — |
| LMArena Search | — | 1171 |
| Vending-Bench 2 | — | 1,107 |
Reasoning Grok 4.1 Fast leads
Grok 3: 13.7 (#333), Grok 4.1 Fast: 43.4 (#49)
| Benchmark | Grok 3 | Grok 4.1 Fast |
|---|---|---|
| SimpleBench | 36.1% | 56% |
| LMArena Hard Prompts | 1434 | 1407 |
| ARC-AGI-2 | 0% | — |
| Kagi LLM Benchmark | 61.3% | — |
| NYT Connections (extended) | — | 87.4% |
| ARC-AGI-1 | 5.5% | — |
| DTBench | — | 87.7% |
| Epoch Capabilities Index | 138.33 | — |
| ForecastBench | — | 61 |
Math Grok 3 leads
Grok 3: 38.0 (#145), Grok 4.1 Fast: 31.9 (#221)
| Benchmark | Grok 3 | Grok 4.1 Fast |
|---|---|---|
| LMArena Math | 1391 | 1408 |
| MathArena Final-Answer Competitions | — | 60.9% |
| OTIS Mock AIME 2024-2025 | 55.6% | — |
| ProofBench | — | 4% |
| Omni-MATH | 46.4% | — |
| MATH Level 5 | 88.7% | — |
| FrontierMath (Feb 2025 set) | 3.8% | — |
| FrontierMath Tier 4 (v1) | 0% | — |
Knowledge Grok 3 leads
Grok 3: 46.2 (#82), Grok 4.1 Fast: 33.1 (#207)
| Benchmark | Grok 3 | Grok 4.1 Fast |
|---|---|---|
| Vectara Hallucination Rate | 5.8% | 17.8% |
| LMArena Expert | 1421 | 1399 |
| GPQA Diamond | 75.8% | — |
| MMLU-Pro | 78.8% | — |
| Confabulations | 14.2% | — |
| GPQA (HELM) | 65% | — |
Multimodal Not comparable
Grok 3: —, Grok 4.1 Fast: 37.0 (#76)
| Benchmark | Grok 3 | Grok 4.1 Fast |
|---|---|---|
| LMArena Vision | — | 1201 |
Multilingual Grok 3 leads
Grok 3: 52.3 (#87), Grok 4.1 Fast: 51.0 (#114)
| Benchmark | Grok 3 | Grok 4.1 Fast |
|---|---|---|
| LMArena Non-English | 1410 | 1391 |
| LMArena Chinese | 1448 | 1441 |
| LMArena French | 1460 | 1415 |
| LMArena German | 1431 | 1404 |
| LMArena Japanese | 1387 | 1349 |
| LMArena Korean | 1373 | 1361 |
| LMArena Russian | 1416 | 1387 |
| LMArena Spanish | 1417 | 1413 |
Instruction Following Grok 3 leads
Grok 3: 75.0 (#73), Grok 4.1 Fast: 72.7 (#133)
| Benchmark | Grok 3 | Grok 4.1 Fast |
|---|---|---|
| LMArena Instruction Following | 1409 | 1376 |
| IFEval | 88.4% | — |
Long Context Grok 4.1 Fast leads
Grok 3: 38.7 (#192), Grok 4.1 Fast: 42.4 (#126)
| Benchmark | Grok 3 | Grok 4.1 Fast |
|---|---|---|
| LMArena Longer Query | 1439 | 1390 |
| Fiction.LiveBench | 58.3% | — |
Writing & Preference Grok 4.1 Fast leads
Grok 3: 55.8 (#141), Grok 4.1 Fast: 57.2 (#131)
| Benchmark | Grok 3 | Grok 4.1 Fast |
|---|---|---|
| LMArena Text | 1426 | 1408 |
| LMArena Creative Writing | 1414 | 1394 |
| EQ-Bench Creative Writing | 1186 | 1327 |
| LMArena Multi-Turn | 1425 | 1389 |
| Short-Story Creative Writing | 76.4% | — |
| WildBench | 84.9% | — |
Frequently asked questions
Is Grok 3 better than Grok 4.1 Fast?
Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 39.9 on the Noometry Index.
Is Grok 3 or Grok 4.1 Fast better for coding?
Grok 3 scores higher on coding benchmarks: 41.9 versus 34.1 in the Noometry coding category.
How many benchmarks do Grok 3 and Grok 4.1 Fast share?
20 benchmarks have published results for both models. Grok 3 has 40 scored results on Noometry and Grok 4.1 Fast has 32.