Claude Sonnet 4.5 vs Grok 4.20 0309 v2
Anthropic vs xAI — benchmarks, pricing, and capabilities side by side.
- •Grok 4.20 0309 v2 has the higher intelligence index (91.1 vs 80.4)
- •Grok 4.20 0309 v2 is cheaper ($2.00 vs $3.00 per 1M input)
- •Grok 4.20 0309 v2 is faster
| Claude Sonnet 4.5 | Grok 4.20 0309 v2 | |
|---|---|---|
| Intelligence index | 80.4 | 91.1 |
| Developer | Anthropic | xAI |
| Type | LLM | LLM |
| Access | API only | — |
| Context window | 1,000,000 tokens | — |
| Input price | $3.00 / 1M | $2.00 / 1M |
| Output price | $15.00 / 1M | $6.00 / 1M |
| Speed | 42 tok/s | 105 tok/s |
| Released | September 29, 2025 | April 7, 2026 |
| Parameters | — | — |
| Input modalities | Text, Image | — |
| Output modalities | Text | — |
Shared benchmarks
Claude Sonnet 4.5
Grok 4.20 0309 v2
GPQA Diamond
83.4
91.1
Humanity’s Last Exam
17.3
32.2