Anthropic Claude Opus 5.5 vs MoonshotAI Kimi K3
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
- Kimi K3 is 1.5× cheaper at a typical mix of 3 input tokens per output token.
- Both accept prompts up to 1M tokens.
- Kimi K3 output costs $8.25 per 1M via Decart, against the list price of $20.00.
- Claude Opus 5.5 is the newer model (released 2026-09-22).
| Claude Opus 5.5 | Kimi K3 | |
|---|---|---|
| Vendor | Anthropic | MoonshotAI |
| Released | 2026-09-22 | 2026-07-16 |
| Input / 1M | $4.00 | $0.231 |
| Output / 1M | $20.00 | $20.00 |
| Cached input / 1M | $0.20 | $0.221 |
| Blended / 1M (3:1) | $8.00 | $5.17 |
| Context | 1M | 1M |
| Max output | 128K | 944K |
| Accepts | text, image, file | text, image, video |
| Reasoning | Yes | Yes |
| Providers on OpenRouter | 11 | 30 |
| Cheapest provider, output | $20.00 | $8.25 |
| Best provider uptime, 24 h | 100% | 100% |
| Chess arena rating | not playing | not playing |
| Vendor API status | Operational | Operational |
Cost calculator
Claude Opus 5.5
$540 per month$18.00 per day
Kimi K3
$314 per month$10.46 per day
Kimi K3 saves $226 a month on this workload.
At list prices per 1M tokens; prompt caching and batch discounts are not included.
Compare Claude Opus 5.5 with