Grok 4.5 vs Kimi K3
Both are Flagship-tier models, from xAI and Moonshot AI respectively. Grok 4.5 is the cheaper choice overall at a 4:1 input:output ratio.
Which is cheaper
Side by side
| Spec | Grok 4.5 | Kimi K3 |
|---|---|---|
| Provider | xAI | Moonshot AI |
| Tier | Flagship | Flagship |
| Context window | 500K | 1.05M |
| Max output | — | — |
| Input $/1M | $2.00 | $3.00 |
| Output $/1M | $6.00 | $15.00 |
| Cache read $/1M | $0.30 | $0.30 |
| Modalities | text, image | text |
Grok 4.5. Short-context rate, for prompts under 200K tokens. At 200K and above: $4 input / $12 output, cache read $0.60 per 1M. Same input and output price as Grok 4.6 with a cheaper cache read; the previous flagship, not marked deprecated.
Kimi K3. input is cache-miss (standard) price per 1M tokens; cache_read is cache-hit price ($0.30).
Sources
Grok 4.5 — verified August 29, 2026