Grok 4.5 vs Kimi K3: Specs & Benchmark Comparison
Grok 4.5 is developed by xAI, while Kimi K3 comes from Moonshot AI. Both were released in July 2026. Kimi K3 has a published size of about 2.8 trillion parameters; xAI has not disclosed the parameter count of Grok 4.5.
We have 4 benchmark results for Grok 4.5 and 3 benchmark results for Kimi K3, but they overlap on a single test: GPQA, where Kimi K3 scores 94.0% against 93.0%.
Grok 4.5 is the cheaper API at $2 per million input tokens and $6 per million output tokens, about 50% below Kimi K3 at $3 and $15. Kimi K3 takes the larger context window at 1M tokens, compared with 500K for Grok 4.5. Both accept text and images as input.
| Characteristic | Grok 4.5 | Kimi K3 |
|---|---|---|
| Company | xAI | Moonshot AI |
| Release Date | July 16, 2026 | July 16, 2026 |
| Parameters | — | 2.8T |
| Multimodal | Yes | Yes |
| Context (input) | 500K | 1.0M |
| Context (output) | — | 1.0M |
| Input Price / 1M | $2.00 | $3.00 |
| Output Price / 1M | $6.00 | $15.00 |
| Average Score | 76.0% | 95.7% |
| Benchmarks | ||
| GPQA | 93.0% | 94.0% |
Visual Benchmark Comparison
Verdict
Both models show equal results — the choice depends on your specific use case.
Both models show comparable average scores: Grok 4.5 — 0.8, Kimi K3 — 1.0.
Grok 4.5 is 2.3x cheaper: input $2.00/1M vs $3.00/1M tokens.
Kimi K3 supports a larger context: 1M vs 500K tokens.
Both models were released around the same time: 7/16/2026 and 7/16/2026.
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Frequently Asked Questions
Which is better for coding — Grok 4.5 or Kimi K3?
Which model is cheaper — Grok 4.5 or Kimi K3?
Which has a larger context window — Grok 4.5 or Kimi K3?
The Grok 4.5 and Kimi K3 comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Grok 4.5 or Kimi K3 page. See also the complete list of AI model comparisons.