Grok 4.5 vs Kimi K3
Grok 4.5 and Kimi K3 are both current production-tier models. Grok 4.5 is meaningfully cheaper at $2 / $6 per 1M. Kimi K3 has a 1.0M context window — about 2× the 500k of Grok 4.5. Kimi K3 leads on long-context retrieval, multilingual.
Specs side by side
| Metric | xAI Grok 4.5 | Z.ai Kimi K3 |
|---|---|---|
| Input price (per 1M) | $2 | $3 |
| Output price (per 1M) | $6 | $15 |
| Context window | 500k tokens | 1.0M tokens |
| Speed tier | balanced | balanced |
| Open weights | No | No |
| EU region | No | No |
| Free tier | No | No |
| Prompt caching | Yes | Yes |
| Vision input | Yes | Yes |
| Extended thinking | Yes | Yes |
When to choose each
Choose Grok 4.5 if…
- Cost is a priority ($2 / $6 per 1M vs $3 / $15 per 1M)
Choose Kimi K3 if…
- You need 1.0M context (2× more than Grok 4.5)
- Long-context retrieval is central to your workload
- Multilingual is central to your workload
Benchmark delta
Grok 4.5 leads on
Grok 4.5 has no meaningful benchmark lead in this pair.
Kimi K3 leads on
- Long-context retrieval
- Multilingual
FAQ — Grok 4.5 vs Kimi K3
Grok 4.5 vs Kimi K3 — which is better?
Grok 4.5 and Kimi K3 are both current production-tier models. Grok 4.5 is meaningfully cheaper at $2 / $6 per 1M. Kimi K3 has a 1.0M context window — about 2× the 500k of Grok 4.5. Kimi K3 leads on long-context retrieval, multilingual. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.
How does Grok 4.5 pricing compare to Kimi K3?
Grok 4.5 costs $2 / $6 per 1M vs Kimi K3 at $3 / $15 per 1M. Grok 4.5 is cheaper on output tokens by roughly 150%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.
Does Grok 4.5 or Kimi K3 have the bigger context window?
Kimi K3 has a 1.0M-token context window — 2× the 500k context of Grok 4.5. Enough for entire codebases, books, or multi-document RAG.
Is there a free tier for Grok 4.5 or Kimi K3?
Grok 4.5: no — X Premium / SuperGrok includes Grok web chat; API is paid. Kimi K3: no — No free API tier; kimi.com web chat is free with limits.
Which is better for coding — Grok 4.5 or Kimi K3?
Kimi K3 leads on coding benchmarks (Grok 4.5: 94/100, Kimi K3: 95/100). For production coding agents also weigh tool-use performance — Grok 4.5 scores 92, Kimi K3 scores 90.