Model comparison
Claude Opus 4 vs Grok 4.1 Fast
Claude Opus 4 is the stronger model overall, scoring 43.1 to 41.4 on the Noometry Index. Grok 4.1 Fast costs 109× less per token, which makes it the better buy when Claude Opus 4's lead doesn't matter for your workload.
Last verified . 24 shared benchmarks.
Summary
- They share 24 benchmarks with published results for both. Claude Opus 4 scores higher in 5 categories and Grok 4.1 Fast in 5 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.1 Fast leads 43.4 to 27.3.
- The biggest single-benchmark swing is DTBench: 81.6% for Claude Opus 4 and 87.7% for Grok 4.1 Fast.
- Grok 4.1 Fast is cheaper at $0.20 / $0.50 per million input/output tokens, against $15 / $75 for Claude Opus 4.
- Claude Opus 4 accepts more context: 200K tokens versus 128K.
Side by side
| Claude Opus 4 | Grok 4.1 Fast | |
|---|---|---|
| Provider | Anthropic | xAI |
| Noometry Index | 43.1 | 41.4 |
| Released | 2025-05-22 | 2025-06-27 |
| Weights | Proprietary | Proprietary |
| Context window | 200K | 128K |
| Max output | 32K | 30K |
| Input $ / M tokens | $15 | $0.20 |
| Output $ / M tokens | $75 | $0.50 |
| Results tracked | 56 | 32 |
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Category by category
Coding Claude Opus 4 leads
Claude Opus 4: 47.2 (#62), Grok 4.1 Fast: 34.1 (#245)
| Benchmark | Claude Opus 4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Coding | 1442 | 1411 |
| SWE-bench Verified | 70.7% | — |
| SWE-bench Verified (bash only) | 67.6% | — |
| Aider Polyglot | 72% | — |
| LMArena WebDev | — | 1242 |
| GSO | 6.9% | — |
| WeirdML | 43.7% | — |
| ALE-Bench | — | 394.93 |
| AlgoTune | 1.33 | — |
Agentic & Tool Use Grok 4.1 Fast leads
Claude Opus 4: 34.8 (#42), Grok 4.1 Fast: 36.3 (#39)
| Benchmark | Claude Opus 4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Search | 1127 | 1171 |
| Berkeley Function Calling Leaderboard | — | 69.6% |
| τ²-bench Banking | — | 13.1% |
| Cybench | 38% | — |
| DeepResearch Bench | 46.8% | — |
| METR Time Horizons | 63.9% | — |
| Vending-Bench 2 | — | 1,107 |
Reasoning Grok 4.1 Fast leads
Claude Opus 4: 27.3 (#121), Grok 4.1 Fast: 43.4 (#49)
| Benchmark | Claude Opus 4 | Grok 4.1 Fast |
|---|---|---|
| SimpleBench | 58.8% | 56% |
| LMArena Hard Prompts | 1399 | 1407 |
| DTBench | 81.6% | 87.7% |
| ForecastBench | 61.1 | 61 |
| ARC-AGI-2 | 8.6% | — |
| Kagi LLM Benchmark | 74.3% | — |
| NYT Connections (extended) | — | 87.4% |
| ARC-AGI-1 | 35.7% | — |
| CritPt | 0.3% | — |
| EnigmaEval | 5.6% | — |
| LMCA | 37.4% | — |
| Epoch Capabilities Index | 142.67 | — |
Math Claude Opus 4 leads
Claude Opus 4: 42.0 (#86), Grok 4.1 Fast: 31.9 (#221)
| Benchmark | Claude Opus 4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Math | 1390 | 1408 |
| MathArena Final-Answer Competitions | — | 60.9% |
| OTIS Mock AIME 2024-2025 | 64.4% | — |
| ProofBench | — | 4% |
| Omni-MATH | 61.6% | — |
| MATH Level 5 | 85% | — |
| FrontierMath (Feb 2025 set) | 4.5% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |
Knowledge Claude Opus 4 leads
Claude Opus 4: 44.0 (#88), Grok 4.1 Fast: 33.1 (#207)
| Benchmark | Claude Opus 4 | Grok 4.1 Fast |
|---|---|---|
| Vectara Hallucination Rate | 12% | 17.8% |
| LMArena Expert | 1386 | 1399 |
| GPQA Diamond | 76.3% | — |
| Humanity's Last Exam | 10.7% | — |
| MMLU-Pro | 87.5% | — |
| Confabulations | 15.9% | — |
| GPQA (HELM) | 70.8% | — |
Multimodal Grok 4.1 Fast leads
Claude Opus 4: 31.5 (#106), Grok 4.1 Fast: 37.0 (#76)
| Benchmark | Claude Opus 4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Vision | 1192 | 1201 |
| GeoBench | 49% | — |
| VPCT | 38% | — |
Multilingual Grok 4.1 Fast leads
Claude Opus 4: 48.8 (#138), Grok 4.1 Fast: 51.0 (#114)
| Benchmark | Claude Opus 4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Non-English | 1362 | 1391 |
| LMArena Chinese | 1386 | 1441 |
| LMArena French | 1372 | 1415 |
| LMArena German | 1391 | 1404 |
| LMArena Japanese | 1331 | 1349 |
| LMArena Korean | 1321 | 1361 |
| LMArena Russian | 1392 | 1387 |
| LMArena Spanish | 1389 | 1413 |
Instruction Following Claude Opus 4 leads
Claude Opus 4: 77.1 (#28), Grok 4.1 Fast: 72.7 (#133)
| Benchmark | Claude Opus 4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Instruction Following | 1406 | 1376 |
| IFEval | 91.8% | — |
Long Context Grok 4.1 Fast leads
Claude Opus 4: 39.6 (#172), Grok 4.1 Fast: 42.4 (#126)
| Benchmark | Claude Opus 4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Longer Query | 1422 | 1390 |
| Fiction.LiveBench | 61.1% | — |
Writing & Preference Claude Opus 4 leads
Claude Opus 4: 61.2 (#89), Grok 4.1 Fast: 57.2 (#131)
| Benchmark | Claude Opus 4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Text | 1377 | 1408 |
| LMArena Creative Writing | 1387 | 1394 |
| EQ-Bench Creative Writing | 1580 | 1327 |
| LMArena Multi-Turn | 1396 | 1389 |
| Short-Story Creative Writing | 83.6% | — |
| WildBench | 85.2% | — |
Frequently asked questions
Is Claude Opus 4 better than Grok 4.1 Fast?
Claude Opus 4 is the stronger model overall, scoring 43.1 to 41.4 on the Noometry Index. Grok 4.1 Fast costs 109× less per token, which makes it the better buy when Claude Opus 4's lead doesn't matter for your workload.
Which is cheaper, Claude Opus 4 or Grok 4.1 Fast?
Grok 4.1 Fast is cheaper. It lists at $0.20 per million input tokens and $0.50 per million output tokens; Claude Opus 4 lists at $15 and $75.
Is Claude Opus 4 or Grok 4.1 Fast better for coding?
Claude Opus 4 scores higher on coding benchmarks: 47.2 versus 34.1 in the Noometry coding category.
Which has the bigger context window?
Claude Opus 4 does, with 200K tokens against 128K.
How many benchmarks do Claude Opus 4 and Grok 4.1 Fast share?
24 benchmarks have published results for both models. Claude Opus 4 has 56 scored results on Noometry and Grok 4.1 Fast has 32.