Model comparison
Claude Haiku 4.5 vs Grok 4 Fast
Claude Haiku 4.5 and Grok 4 Fast score almost the same on the Noometry Index (39.5 vs 39.4), so choose on price, context window or the category you care about most.
Last verified . 25 shared benchmarks.
Summary
- They share 25 benchmarks with published results for both. Claude Haiku 4.5 scores higher in 4 categories and Grok 4 Fast in 5 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in long context, where Grok 4 Fast leads 63.2 to 43.6.
- The biggest single-benchmark swing is Vectara Hallucination Rate: 9.8% for Claude Haiku 4.5 and 19.7% for Grok 4 Fast.
Side by side
| Claude Haiku 4.5 | Grok 4 Fast | |
|---|---|---|
| Provider | Anthropic | xAI |
| Noometry Index | 39.5 | 39.4 |
| Released | 2025-10-15 | 2025-09-19 |
| Weights | Proprietary | Proprietary |
| Context window | 200K | — |
| Max output | 64K | — |
| Input $ / M tokens | $1 | — |
| Output $ / M tokens | $5 | — |
| Results tracked | 53 | 30 |
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Category by category
Coding Claude Haiku 4.5 leads
Claude Haiku 4.5: 44.0 (#78), Grok 4 Fast: 32.5 (#271)
| Benchmark | Claude Haiku 4.5 | Grok 4 Fast |
|---|---|---|
| LMArena WebDev | 1330 | 1159 |
| WeirdML | 45.4% | 42.9% |
| LMArena Coding | 1453 | 1429 |
| SWE-bench Verified (bash only) | 66.6% | — |
| SWE-bench Multilingual | 64.7% | — |
| SciCode | 43.3% | — |
| ALE-Bench | 653.48 | — |
Agentic & Tool Use Claude Haiku 4.5 leads
Claude Haiku 4.5: 33.6 (#52), Grok 4 Fast: 29.5 (#86)
| Benchmark | Claude Haiku 4.5 | Grok 4 Fast |
|---|---|---|
| Terminal-Bench | 35.5% | — |
| Berkeley Function Calling Leaderboard | 68.7% | — |
| τ²-bench Banking | — | 15.7% |
| Cybench | — | 30% |
| DeepResearch Bench | 45.5% | — |
| BALROG | 31.2% | — |
| ExploitBench | 13.7% | — |
| LMArena Search | — | 1171 |
| Vending-Bench 2 | 458.89 | — |
Reasoning Grok 4 Fast leads
Claude Haiku 4.5: 15.1 (#320), Grok 4 Fast: 22.2 (#201)
| Benchmark | Claude Haiku 4.5 | Grok 4 Fast |
|---|---|---|
| ARC-AGI-2 | 4% | 5.3% |
| ARC-AGI-1 | 47.7% | 48.5% |
| LMArena Hard Prompts | 1420 | 1412 |
| DTBench | 73.6% | 82.7% |
| Epoch Capabilities Index | 142.41 | 144.2 |
| ForecastBench | 61.4 | 60.5 |
| Kagi LLM Benchmark | — | 66.1% |
| NYT Connections (extended) | 14.3% | — |
| CritPt | 0% | — |
| Chess Puzzles | 8% | — |
| LMCA | 30.9% | — |
Math Claude Haiku 4.5 leads
Claude Haiku 4.5: 44.9 (#78), Grok 4 Fast: 38.9 (#123)
| Benchmark | Claude Haiku 4.5 | Grok 4 Fast |
|---|---|---|
| LMArena Math | 1396 | 1419 |
| OTIS Mock AIME 2024-2025 | 66.7% | — |
| Omni-MATH | 56.1% | — |
| MATH Level 5 | 96.4% | — |
| FrontierMath (Feb 2025 set) | 5.9% | — |
| FrontierMath Tier 4 (v1) | 2.1% | — |
Knowledge Claude Haiku 4.5 leads
Claude Haiku 4.5: 37.7 (#153), Grok 4 Fast: 32.0 (#214)
| Benchmark | Claude Haiku 4.5 | Grok 4 Fast |
|---|---|---|
| Vectara Hallucination Rate | 9.8% | 19.7% |
| LMArena Expert | 1442 | 1411 |
| GPQA Diamond | 71.2% | — |
| SimpleQA Verified | 13.2% | — |
| MMLU-Pro | 77.7% | — |
| GPQA (HELM) | 60.5% | — |
Multimodal Not comparable
Claude Haiku 4.5: 26.8 (#118), Grok 4 Fast: —
| Benchmark | Claude Haiku 4.5 | Grok 4 Fast |
|---|---|---|
| Blueprint-Bench 2 | 0% | — |
| LMArena Document | 1420 | — |
Multilingual Grok 4 Fast leads
Claude Haiku 4.5: 49.9 (#129), Grok 4 Fast: 51.3 (#111)
| Benchmark | Claude Haiku 4.5 | Grok 4 Fast |
|---|---|---|
| LMArena Non-English | 1377 | 1396 |
| LMArena Chinese | 1417 | 1457 |
| LMArena French | 1408 | 1431 |
| LMArena German | 1375 | 1383 |
| LMArena Japanese | 1339 | 1352 |
| LMArena Korean | 1347 | 1357 |
| LMArena Russian | 1381 | 1389 |
| LMArena Spanish | 1420 | 1415 |
Instruction Following Grok 4 Fast leads
Claude Haiku 4.5: 71.4 (#149), Grok 4 Fast: 73.2 (#121)
| Benchmark | Claude Haiku 4.5 | Grok 4 Fast |
|---|---|---|
| LMArena Instruction Following | 1414 | 1387 |
| IFEval | 80.1% | — |
Long Context Grok 4 Fast leads
Claude Haiku 4.5: 43.6 (#92), Grok 4 Fast: 63.2 (#3)
| Benchmark | Claude Haiku 4.5 | Grok 4 Fast |
|---|---|---|
| LMArena Longer Query | 1427 | 1415 |
| Fiction.LiveBench | — | 94.4% |
Writing & Preference Grok 4 Fast leads
Claude Haiku 4.5: 57.9 (#123), Grok 4 Fast: 60.0 (#102)
| Benchmark | Claude Haiku 4.5 | Grok 4 Fast |
|---|---|---|
| LMArena Text | 1396 | 1407 |
| LMArena Creative Writing | 1372 | 1387 |
| LMArena Multi-Turn | 1409 | 1414 |
| WildBench | 83.9% | — |
| EQ-Bench 4 | 1064 | — |
Frequently asked questions
Is Claude Haiku 4.5 better than Grok 4 Fast?
Claude Haiku 4.5 and Grok 4 Fast score almost the same on the Noometry Index (39.5 vs 39.4), so choose on price, context window or the category you care about most.
Is Claude Haiku 4.5 or Grok 4 Fast better for coding?
Claude Haiku 4.5 scores higher on coding benchmarks: 44.0 versus 32.5 in the Noometry coding category.
How many benchmarks do Claude Haiku 4.5 and Grok 4 Fast share?
25 benchmarks have published results for both models. Claude Haiku 4.5 has 53 scored results on Noometry and Grok 4 Fast has 30.