Claude Sonnet 5 vs Grok-4.20 Reasoning — Price, Context, and Capability Compared
Claude Sonnet 5 vs Grok-4.20 Reasoning: which should I use?
Claude Sonnet 5 costs 2.0× more per blended million tokens than Grok-4.20 Reasoning. Grok-4.20 Reasoning has the larger context window (1,000,000 tokens). Default to Grok-4.20 Reasoning unless you specifically need Claude Sonnet 5's edge.
Spec comparison
| Claude Sonnet 5 | Grok-4.20 Reasoning | |
|---|---|---|
| Price (input) | $3.00/M | $2.00/M ✓ |
| Price (output) | $15.00/M | $6.00/M ✓ |
| Blended price | $6.00/M | $3.00/M ✓ |
| Context window | 500,000 tokens | 1,000,000 tokens ✓ |
| Max output | 64,000 tokens | 64,000 tokens |
| Modalities | text, vision | text, vision |
| Reasoning mode | Yes | Yes |
| Released | 2026-08 | 2026-03 |
| Speed | Not measured | 52 t/s |
Cost at scale (3:1 blended)
| Tokens / month | Claude Sonnet 5 | Grok-4.20 Reasoning | Delta |
|---|---|---|---|
| 1,000,000 | $6.00 | $3.00 | $3.00 (2.0×) |
| 10,000,000 | $60.00 | $30.00 | $30.00 (2.0×) |
| 100,000,000 | $600.00 | $300.00 | $300.00 (2.0×) |
Choose Claude Sonnet 5 if…
- ✓Frontier intelligence at Sonnet economics
- ✓Fast interactive coding performance
- ✓Reliable structured output and extended thinking
- ✓Production workloads that need near-Opus quality with better speed and cost.
Choose Grok-4.20 Reasoning if…
- ✓State-of-the-art document analysis at 1M context
- ✓Dedicated reasoning mode
- ✓Strong vision understanding
- ✓Long-document analysis and problems that benefit from explicit reasoning.
Run this exact matchup right now
Send the same prompt to Claude Sonnet 5 and Grok-4.20 Reasoning side by side and see the outputs yourself.
Try Claude Sonnet 5 vs Grok-4.20 Reasoning FreeFAQ
Is Claude Sonnet 5 cheaper than Grok-4.20 Reasoning?
Grok-4.20 Reasoning is cheaper, at $3.00 per million blended tokens vs $6.00 for Claude Sonnet 5.
Which has the bigger context window, Claude Sonnet 5 or Grok-4.20 Reasoning?
Grok-4.20 Reasoning has the larger context window: 1,000,000 tokens vs 500,000.
Can Claude Sonnet 5 replace Grok-4.20 Reasoning for coding?
Both are viable for coding. Frontier intelligence at Sonnet economics (Claude Sonnet 5) vs State-of-the-art document analysis at 1M context (Grok-4.20 Reasoning) — pick based on which strength matters more for your workload.
Neither of these? See Claude Sonnet 5 alternatives or Grok-4.20 Reasoning alternatives.
Related
Pricing verified 2026-04-06. Specs verified 2026-08-08.