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Grok 4.5 vs Grok 4 Fast
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| Attribute | Grok 4.5 | Grok 4 Fast |
|---|---|---|
| Scores | ||
| Intelligence (ECI) | 154 | 144 |
| Coding | 89 | 41 |
| Math | 84 | 49 |
| Reasoning & Knowledge | 68 | 33 |
| Agentic & Tools | 74 | 23 |
| Specifications | ||
| Developer | xAI | xAI |
| Family | Grok | Grok |
| Released | Jul 8, 2026 | Sep 19, 2025 |
| Parameters | — | — |
| Availability | API access | API access |
| Context window | 500K | — |
| Price — $/M input | $2.00 | — |
| Price — $/M output | $6.00 | — |
| Inputs | text, image, file | — |
| Outputs | text | — |
| Benchmarks | ||
| AIME 2024/2025 | 98% | 90% |
| APEX | 34% | — |
| ARC-AGI | 87% | 49% |
| ARC-AGI-2 | 53% | 5% |
| GPQA Diamond | 93% | 85% |
| Humanity's Last Exam | 40% | 17% |
| SciCode | 54% | 44% |
| SimpleBench | 70% | — |
| SimpleQA Verified | 54% | — |
| WebDev Arena | 1551 | 1149 |
| WeirdML | 46% | 43% |
| LiveCodeBench | — | 83% |
| MMLU-Pro | — | 85% |
| τ²-bench | — | 66% |
Use-case scores are 0–100 percentile composites across each area’s benchmarks, ranked against every model from the past year. Highlighted cells lead each row. Open a model for the full picture.
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Benchmarks & model data from Epoch AI (CC BY); pricing & specs from OpenRouter. ECI = Epoch Capabilities Index.