Claude Sonnet 4.5 vs Grok 4.5
Claude Sonnet 4.5 (Anthropic) and Grok 4.5 (xAI) compared on benchmarks, pricing, context window, and use-case rankings.
- Grok 4.5 leads on overall intelligence (ECI 154 vs 147).
- Grok 4.5 is cheaper on input tokens — $2.00 vs $3.00 per 1M.
- Claude Sonnet 4.5 has a larger context window (1M vs 500K tokens).
- Grok 4.5 ranks higher for coding (91th vs 34th percentile).
| Attribute | Claude Sonnet 4.5 | Grok 4.5 |
|---|---|---|
| Scores | ||
| Intelligence (ECI) | 147 | 154 |
| Coding | 34 | 91 |
| Math | 32 | 85 |
| Reasoning & Knowledge | 31 | 70 |
| Agentic & Tools | 39 | 75 |
| Specifications | ||
| Developer | Anthropic | xAI |
| Family | Claude | Grok |
| Released | Sep 29, 2025 | Jul 8, 2026 |
| Parameters | — | — |
| Availability | API access | API access |
| Context window | 1M | 500K |
| Price — $/M input | $3.00 | $2.00 |
| Price — $/M output | $15.00 | $6.00 |
| Inputs | text, image, file | text, image, file |
| Outputs | text | text |
| Benchmarks | ||
| AIME 2024/2025 | 78% | 98% |
| ARC-AGI | 64% | 87% |
| ARC-AGI-2 | 14% | 53% |
| FrontierMath | 15% | — |
| FrontierMath Tier 4 | 4% | — |
| GDPval (win/tie rate) | 50% | — |
| GPQA Diamond | 82% | 93% |
| GSO (code optimization) | 15% | — |
| Humanity's Last Exam | 14% | 40% |
| MATH Level 5 | 98% | — |
| METR task horizon | 2.0 h | — |
| SimpleBench | 54% | 70% |
| SimpleQA Verified | 24% | 54% |
| SWE-bench Verified | 71% | — |
| Terminal-Bench | 47% | — |
| WebDev Arena | 1391 | 1551 |
| WeirdML | 48% | 46% |
| APEX | — | 34% |
| SciCode | — | 54% |
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.
Frequently asked questions
Is Claude Sonnet 4.5 better than Grok 4.5?
On Epoch AI's Capabilities Index, Grok 4.5 scores higher (154) than Claude Sonnet 4.5 (147). The right pick depends on your task — compare their coding, math, and reasoning scores in the table above.
Which is cheaper, Claude Sonnet 4.5 or Grok 4.5?
Grok 4.5 is cheaper on input tokens at $2.00 per million, versus $3.00 (representative OpenRouter pricing).
Which has a larger context window, Claude Sonnet 4.5 or Grok 4.5?
Claude Sonnet 4.5 supports up to 1M tokens, compared with 500K for the other.
Which is better for coding, Claude Sonnet 4.5 or Grok 4.5?
Across coding benchmarks like SWE-bench Verified and Terminal-Bench, Grok 4.5 ranks higher — 91th vs 34th percentile among the models tracked on Model Beat.
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Benchmarks & model data from Epoch AI (CC BY); pricing & specs from OpenRouter. ECI = Epoch Capabilities Index.