Model Comparison
Grok 4.5 vs Kimi K3Which is better in 2026?
Kimi K3 significantly outperforms across most benchmarks. Grok 4.5 is 2.0x cheaper per token.
Verdict: Grok 4.5 vs Kimi K3 — which is better?
Grok 4.5 (by xAI) and Kimi K3 (by Moonshot AI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
Grok 4.5 outperforms in 0 benchmarks, while Kimi K3 is better at 5 benchmarks (DeepSWE, GDPval-AA, GPQA, SWE-Marathon, Terminal-Bench 2.1). Kimi K3 significantly outperforms across most benchmarks.
On price, Grok 4.5 is roughly 2.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Kimi K3 also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Choose Grok 4.5 if…
- cost matters — it's about 2.0x cheaper per token
Choose Kimi K3 if…
- you want the strongest raw capability — it leads on 5 of 5 shared benchmarks
- you process long inputs — it offers a 1,048,576 token context window
Performance Benchmarks
Comparative analysis across standard metrics
Grok 4.5 outperforms in 0 benchmarks, while Kimi K3 is better at 5 benchmarks (DeepSWE, GDPval-AA, GPQA, SWE-Marathon, Terminal-Bench 2.1).
Kimi K3 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Grok 4.5 ($2.00/1M tokens) is 1.5x cheaper than Kimi K3 ($3.00/1M tokens).
For output processing, Grok 4.5 ($6.00/1M tokens) is 2.5x cheaper than Kimi K3 ($15.00/1M tokens).
In conclusion, Kimi K3 is more expensive than Grok 4.5.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Kimi K3 accepts 1,048,576 input tokens compared to Grok 4.5's 500,000 tokens. Only Kimi K3 specifies output context (1,048,576 tokens).
Input Capabilities
Supported data types and modalities
Both Grok 4.5 and Kimi K3 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Grok 4.5
Kimi K3
Release Timeline
When each model was launched
Both models were released on 2026-07-16.
They likely represent similar generations of model development.
Jul 16, 2026
2 days ago
Jul 16, 2026
2 days ago
Knowledge Cutoff
When training data ends
Grok 4.5 has a documented knowledge cutoff of 2026-02-01, while Kimi K3's cutoff date is not specified.
We can confirm Grok 4.5's training data extends to 2026-02-01, but cannot make a direct comparison without Kimi K3's cutoff date.
Feb 2026
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Provider Availability
Grok 4.5 is available from xAI. Kimi K3 is available from Moonshot AI.
Grok 4.5
Kimi K3
Outputs Comparison
Key Takeaways
Kimi K3
View detailsMoonshot AI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Grok 4.5 and Kimi K3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Grok 4.5 vs Kimi K3.