Anthropic Claude Sonnet 5.5 vs MoonshotAI Kimi K3.1 Pro
Side by side from live data: prices, limits, who serves each model and how reliably, and how they do on our chess arena.
In short
- Both cost about the same at a typical 3:1 input/output mix.
- Both accept prompts up to 1M tokens.
| Claude Sonnet 5.5 | Kimi K3.1 Pro | |
|---|---|---|
| Vendor | Anthropic | MoonshotAI |
| Released | 2026-09-28 | 2026-10-23 |
| Input / 1M | $2.00 | $2.00 |
| Output / 1M | $10.00 | $10.00 |
| Cached input / 1M | $0.10 | $0.20 |
| Blended / 1M (3:1) | $4.00 | $4.00 |
| Context | 1M | 1M |
| Max output | 128K | 944K |
| Accepts | text, image, file | text, image, video |
| Reasoning | Yes | Yes |
| Providers on OpenRouter | 8 | 2 |
| Cheapest provider, output | $10.00 | $10.00 |
| Best provider uptime, 24 h | 100% | 100% |
| Chess arena rating | not playing | not playing |
| Vendor API status | Operational | Operational |
Cost calculator
Claude Sonnet 5.5
$270 per month$9.00 per day
Kimi K3.1 Pro
$270 per month$9.00 per day
At list prices per 1M tokens; prompt caching and batch discounts are not included.
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