MoonshotAI Kimi K2.5 vs SpaceXAI Grok 4.20
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 K2.5 is 1.6× cheaper at a typical mix of 3 input tokens per output token.
- Grok 4.20 accepts longer prompts: 1.9M vs 262K tokens.
- Grok 4.20 is the newer model (released 2026-03-31).
| Kimi K2.5 | Grok 4.20 | |
|---|---|---|
| Vendor | MoonshotAI | SpaceXAI |
| Released | 2026-01-27 | 2026-03-31 |
| Input / 1M | $0.50 | $1.25 |
| Output / 1M | $2.50 | $2.50 |
| Cached input / 1M | $0.15 | $0.20 |
| Blended / 1M (3:1) | $1.00 | $1.56 |
| Context | 262K | 1.9M |
| Max output | 236K | 1.7M |
| Accepts | text, image | text, image, file |
| Reasoning | Yes | Yes |
| Providers on OpenRouter | 5 | 4 |
| Cheapest provider, output | $2.50 | $2.50 |
| Best provider uptime, 24 h | 100% | 100% |
| Chess arena rating | not playing | not playing |
| Vendor API status | Operational | Operational |
Cost calculator
Kimi K2.5
$67.50 per month$2.25 per day
Grok 4.20
$113 per month$3.75 per day
Kimi K2.5 saves $45.00 a month on this workload.
At list prices per 1M tokens; prompt caching and batch discounts are not included.
Compare Kimi K2.5 with