Claude Sonnet 4.6 vs Grok Code Fast 2 for coding
Grok Code Fast 2 is the stronger coder of the two on benchmarks, but Claude Sonnet 4.6 can be the better pick when cost, speed, or context window matter more. Below: a side-by-side spec table and exactly when to pick each.
At a glance
| Spec | Claude Sonnet 4.6 | Grok Code Fast 2 |
|---|---|---|
| Provider | Anthropic | xAI |
| Released | Sep 2025 | Dec 2025 |
| SWE-bench Verified | 64% | 65% |
| HumanEval | 92% | 91% |
| MMLU | 86% | 85% |
| Context window | 200K | 256K |
| Max output | 64K | 32K |
| Input price (per 1M) | $3 | $0.20 |
| Output price (per 1M) | $15 | $1.50 |
| Price tier | Mid | Budget |
| Speed | Standard | Fast |
| Hosting | Closed/API | Closed/API |
| Modality | Multimodal (vision) | Text |
| Knowledge cutoff | Apr 2024 | Nov 2025 |
Pick Claude Sonnet 4.6 if…
- It's tuned for day-to-day coding, fast agentic loops, balanced cost/quality.
Pick Grok Code Fast 2 if…
- It scores higher on SWE-bench Verified (65% vs 64%), the best proxy for real-world coding.
- It's cheaper (Budget tier vs Mid).
- It has a larger context window (256K vs 200K).
- It responds faster (Fast).
Claude Sonnet 4.6 vs Grok Code Fast 2: which is better for coding?
Grok Code Fast 2 is the stronger coder of the two on benchmarks, but Claude Sonnet 4.6 can be the better pick when cost, speed, or context window matter more. See the full spec table for SWE-bench, HumanEval, MMLU, context window, and pricing on both. Benchmarks are a directional signal, not a guarantee for your codebase — the most reliable test is running both on a real task you care about.
Compare these head-to-head with live data, or build a full stack around your pick — Flowpicker shows compatibility and monthly cost.
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See the full model leaderboard ranked by SWE-bench, HumanEval, and MMLU.