Model comparison
Granite 4.2 8B vs Grok 4 Fast
Granite 4.2 8B is the stronger model overall, scoring 40.5 to 39.4 on the Noometry Index.
Last verified . 11 shared benchmarks.
Summary
- They share 11 benchmarks with published results for both. Granite 4.2 8B scores higher in 3 categories and Grok 4 Fast in 4 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in long context, where Grok 4 Fast leads 63.2 to 40.3.
- Granite 4.2 8B has downloadable open weights; the other is API-only.
Side by side
| Granite 4.2 8B | Grok 4 Fast | |
|---|---|---|
| Provider | IBM | xAI |
| Noometry Index | 40.5 | 39.4 |
| Released | — | 2025-09-19 |
| Weights | Open | Proprietary |
| Context window | 131K | — |
| Max output | 118K | — |
| Input $ / M tokens | $0.06 | — |
| Output $ / M tokens | $0.25 | — |
| Results tracked | 11 | 30 |
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Category by category
Coding Granite 4.2 8B leads
Granite 4.2 8B: 40.5 (#137), Grok 4 Fast: 32.5 (#271)
| Benchmark | Granite 4.2 8B | Grok 4 Fast |
|---|---|---|
| LMArena Coding | 1380 | 1429 |
| LMArena WebDev | — | 1159 |
| WeirdML | — | 42.9% |
Agentic & Tool Use Not comparable
Granite 4.2 8B: —, Grok 4 Fast: 29.5 (#86)
| Benchmark | Granite 4.2 8B | Grok 4 Fast |
|---|---|---|
| τ²-bench Banking | — | 15.7% |
| Cybench | — | 30% |
| LMArena Search | — | 1171 |
Reasoning Granite 4.2 8B leads
Granite 4.2 8B: 26.6 (#131), Grok 4 Fast: 22.2 (#201)
| Benchmark | Granite 4.2 8B | Grok 4 Fast |
|---|---|---|
| LMArena Hard Prompts | 1329 | 1412 |
| ARC-AGI-2 | — | 5.3% |
| Kagi LLM Benchmark | — | 66.1% |
| ARC-AGI-1 | — | 48.5% |
| DTBench | — | 82.7% |
| Epoch Capabilities Index | — | 144.2 |
| ForecastBench | — | 60.5 |
Math Not comparable
Granite 4.2 8B: —, Grok 4 Fast: 38.9 (#123)
| Benchmark | Granite 4.2 8B | Grok 4 Fast |
|---|---|---|
| LMArena Math | — | 1419 |
Knowledge Granite 4.2 8B leads
Granite 4.2 8B: 38.4 (#145), Grok 4 Fast: 32.0 (#214)
| Benchmark | Granite 4.2 8B | Grok 4 Fast |
|---|---|---|
| LMArena Expert | 1384 | 1411 |
| Vectara Hallucination Rate | — | 19.7% |
Multilingual Grok 4 Fast leads
Granite 4.2 8B: 44.5 (#178), Grok 4 Fast: 51.3 (#111)
| Benchmark | Granite 4.2 8B | Grok 4 Fast |
|---|---|---|
| LMArena Non-English | 1302 | 1396 |
| LMArena Chinese | 1366 | 1457 |
| LMArena Russian | 1285 | 1389 |
| LMArena French | — | 1431 |
| LMArena German | — | 1383 |
| LMArena Japanese | — | 1352 |
| LMArena Korean | — | 1357 |
| LMArena Spanish | — | 1415 |
Instruction Following Grok 4 Fast leads
Granite 4.2 8B: 68.7 (#184), Grok 4 Fast: 73.2 (#121)
| Benchmark | Granite 4.2 8B | Grok 4 Fast |
|---|---|---|
| LMArena Instruction Following | 1301 | 1387 |
Long Context Grok 4 Fast leads
Granite 4.2 8B: 40.3 (#159), Grok 4 Fast: 63.2 (#3)
| Benchmark | Granite 4.2 8B | Grok 4 Fast |
|---|---|---|
| LMArena Longer Query | 1324 | 1415 |
| Fiction.LiveBench | — | 94.4% |
Writing & Preference Grok 4 Fast leads
Granite 4.2 8B: 49.6 (#189), Grok 4 Fast: 60.0 (#102)
| Benchmark | Granite 4.2 8B | Grok 4 Fast |
|---|---|---|
| LMArena Text | 1320 | 1407 |
| LMArena Creative Writing | 1236 | 1387 |
| LMArena Multi-Turn | 1301 | 1414 |
Frequently asked questions
Is Granite 4.2 8B better than Grok 4 Fast?
Granite 4.2 8B is the stronger model overall, scoring 40.5 to 39.4 on the Noometry Index.
Is Granite 4.2 8B or Grok 4 Fast better for coding?
Granite 4.2 8B scores higher on coding benchmarks: 40.5 versus 32.5 in the Noometry coding category.
How many benchmarks do Granite 4.2 8B and Grok 4 Fast share?
11 benchmarks have published results for both models. Granite 4.2 8B has 11 scored results on Noometry and Grok 4 Fast has 30.