Model comparison
Grok 4 Fast vs Inkling
Inkling is the stronger model overall, scoring 44.1 to 39.0 on the Noometry Index.
Last verified . 24 shared benchmarks.
Summary
- They share 24 benchmarks with published results for both. Grok 4 Fast scores higher in 2 categories and Inkling in 7 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where Inkling leads 55.2 to 31.5.
- The biggest single-benchmark swing is ARC-AGI-2: 5.3% for Grok 4 Fast and 36.5% for Inkling.
- Inkling has downloadable open weights; the other is API-only.
Side by side
| Grok 4 Fast | Inkling | |
|---|---|---|
| Provider | xAI | Thinking Machines Lab |
| Noometry Index | 39.0 | 44.1 |
| Released | 2025-09-19 | 2026-07-15 |
| Weights | Proprietary | Open |
| Context window | — | 66K |
| Max output | — | 66K |
| Input $ / M tokens | — | $1.87 |
| Output $ / M tokens | — | $4.68 |
| Results tracked | 30 | 41 |
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Category by category
Coding Inkling leads
Grok 4 Fast: 32.3 (#264), Inkling: 34.1 (#229)
| Benchmark | Grok 4 Fast | Inkling |
|---|---|---|
| LMArena WebDev | 1160 | 1412 |
| WeirdML | 42.9% | 32.3% |
| LMArena Coding | 1429 | 1463 |
| FrontierCode | — | 14% |
| FrontierSWE | — | 4.1% |
| SciCode | — | 47% |
| ALE-Bench | — | 946 |
Agentic & Tool Use Too close to call
Grok 4 Fast: 29.3 (#80), Inkling: 29.5 (#76)
| Benchmark | Grok 4 Fast | Inkling |
|---|---|---|
| τ²-bench Banking | 15.7% | 25% |
| APEX-Agents | — | 33.8% |
| Cybench | 30% | — |
| LMArena Search | 1171 | — |
Reasoning Inkling leads
Grok 4 Fast: 22.5 (#179), Inkling: 40.6 (#48)
| Benchmark | Grok 4 Fast | Inkling |
|---|---|---|
| ARC-AGI-2 | 5.3% | 36.5% |
| ARC-AGI-1 | 48.5% | 79.5% |
| LMArena Hard Prompts | 1413 | 1452 |
| DTBench | 82.7% | 87.5% |
| Epoch Capabilities Index | 144.21 | 148.6 |
| SimpleBench | — | 50% |
| Kagi LLM Benchmark | 66.1% | — |
| CritPt | — | 5.4% |
| Chess Puzzles | — | 21% |
| LMCA | — | 37.6% |
| ForecastBench | 60.5 | — |
Math Grok 4 Fast leads
Grok 4 Fast: 36.1 (#126), Inkling: 31.2 (#198)
| Benchmark | Grok 4 Fast | Inkling |
|---|---|---|
| LMArena Math | 1419 | 1482 |
| FrontierMath (Tiers 1-3) | — | 33.3% |
| FrontierMath Tier 4 | — | 4.9% |
| OTIS Mock AIME 2024-2025 | — | 88.9% |
| ProofBench | — | 0% |
Knowledge Inkling leads
Grok 4 Fast: 31.5 (#211), Inkling: 55.2 (#44)
| Benchmark | Grok 4 Fast | Inkling |
|---|---|---|
| LMArena Expert | 1411 | 1468 |
| GPQA Diamond | — | 88.3% |
| SimpleQA Verified | — | 40.3% |
| Vectara Hallucination Rate | 19.7% | — |
Multilingual Inkling leads
Grok 4 Fast: 51.5 (#106), Inkling: 54.2 (#49)
| Benchmark | Grok 4 Fast | Inkling |
|---|---|---|
| LMArena Non-English | 1397 | 1434 |
| LMArena Chinese | 1458 | 1495 |
| LMArena French | 1433 | 1453 |
| LMArena German | 1383 | 1456 |
| LMArena Japanese | 1358 | 1428 |
| LMArena Korean | 1359 | 1401 |
| LMArena Russian | 1387 | 1430 |
| LMArena Spanish | 1414 | 1442 |
Instruction Following Inkling leads
Grok 4 Fast: 73.4 (#116), Inkling: 75.3 (#65)
| Benchmark | Grok 4 Fast | Inkling |
|---|---|---|
| LMArena Instruction Following | 1388 | 1427 |
Long Context Grok 4 Fast leads
Grok 4 Fast: 63.2 (#3), Inkling: 43.9 (#79)
| Benchmark | Grok 4 Fast | Inkling |
|---|---|---|
| LMArena Longer Query | 1415 | 1436 |
| Fiction.LiveBench | 94.4% | — |
Writing & Preference Inkling leads
Grok 4 Fast: 60.2 (#96), Inkling: 65.5 (#48)
| Benchmark | Grok 4 Fast | Inkling |
|---|---|---|
| LMArena Text | 1407 | 1443 |
| LMArena Creative Writing | 1388 | 1390 |
| LMArena Multi-Turn | 1414 | 1436 |
| EQ-Bench Creative Writing | — | 1611 |
| EQ-Bench 4 | — | 1226 |
Frequently asked questions
Is Grok 4 Fast better than Inkling?
Inkling is the stronger model overall, scoring 44.1 to 39.0 on the Noometry Index.
Is Grok 4 Fast or Inkling better for coding?
Inkling scores higher on coding benchmarks: 34.1 versus 32.3 in the Noometry coding category.
How many benchmarks do Grok 4 Fast and Inkling share?
24 benchmarks have published results for both models. Grok 4 Fast has 30 scored results on Noometry and Inkling has 41.