Claude Sonnet 4.5 vs Grok 4
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Claude Sonnet 4.5
65.5Anthropic · Sep 2025
The model that made 30-hour autonomous coding sessions real — 77.2% SWE-bench Verified and a 1M-token context beta at $3/$15.
Grok 4
xAI · Jul 2025
xAI's mid-2025 flagship, trained on the 200K-GPU Colossus cluster — a math and science reasoning standout of its generation.
The verdict
Grok 4 wins 3 of the 3 benchmarks these models share, against 0 for Claude Sonnet 4.5. Grok 4 also takes 256K of context versus 200K for Claude Sonnet 4.5.
Benchmark head-to-head 0–3
Specs & pricing
| Claude Sonnet 4.5 | Grok 4 | |
|---|---|---|
| modhub Index | 65.5 | — |
| Input price / 1M | $3 | $3 |
| Output price / 1M | $15 | $15 |
| Context window | 200K | 256K |
| Max output | 64K | — |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text, image | text, image |
| Knowledge cutoff | Jan 2025 | Jul 2025 |
| Released | Sep 2025 | Jul 2025 |
| Example monthly cost* | $52.50 | $52.50 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, Claude Sonnet 4.5 or Grok 4?
- Grok 4 wins 3 of the 3 benchmarks these models share, against 0 for Claude Sonnet 4.5. Grok 4 also takes 256K of context versus 200K for Claude Sonnet 4.5.
- Which is cheaper, Claude Sonnet 4.5 or Grok 4?
- Claude Sonnet 4.5 costs $3/$15 per million input/output tokens, while Grok 4 costs $3/$15. For a typical workload of 10M input and 1.5M output tokens per month, that's $52.50 versus $52.50.
- Which model is better for coding, Claude Sonnet 4.5 or Grok 4?
- We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.