Grok Code Fast 1 vs Kimi K2-Thinking-0905
Kimi K2-Thinking-0905 significantly outperforms across most benchmarks. Grok Code Fast 1 is 1.6x cheaper per token.
xAI · Moonshot AI · Updated for 2026
Which is better?
Grok Code Fast 1 outperforms in 0 benchmarks, while Kimi K2-Thinking-0905 is better at 1 benchmark (SWE-Bench Verified). Kimi K2-Thinking-0905 significantly outperforms across most benchmarks.
On price, Grok Code Fast 1 is roughly 1.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Kimi K2-Thinking-0905 also accepts a larger context window (262,144 input tokens), making it the stronger choice for long documents and large codebases.
Based on current benchmark, pricing, and model metadata for 2026.
Choose Grok Code Fast 1
- cost matters — it's about 1.6x cheaper per token
Choose Kimi K2-Thinking-0905
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- you process long inputs — it offers a 262,144 token context window
- you want the most recent training data — it shipped Sep 2025
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
Grok Code Fast 1 outperforms in 0 benchmarks, while Kimi K2-Thinking-0905 is better at 1 benchmark (SWE-Bench Verified).
Kimi K2-Thinking-0905 significantly outperforms across most benchmarks.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Grok Code Fast 1 ($0.20/1M tokens) is 2.3x cheaper than Kimi K2-Thinking-0905 ($0.47/1M tokens).
For output processing, Grok Code Fast 1 ($1.50/1M tokens) is 1.3x cheaper than Kimi K2-Thinking-0905 ($2.00/1M tokens).
In conclusion, Kimi K2-Thinking-0905 is more expensive than Grok Code Fast 1.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Kimi K2-Thinking-0905 accepts 262,144 input tokens compared to Grok Code Fast 1's 256,000 tokens. Kimi K2-Thinking-0905 can generate longer responses up to 262,144 tokens, while Grok Code Fast 1 is limited to 10,000 tokens.
License
Usage and distribution terms
Grok Code Fast 1 is licensed under a proprietary license, while Kimi K2-Thinking-0905 uses MIT.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
MIT
Open weights
Release Timeline
When each model was launched
Grok Code Fast 1 was released on 2025-08-28, while Kimi K2-Thinking-0905 was released on 2025-09-05.
Kimi K2-Thinking-0905 is 0 month newer than Grok Code Fast 1.
Aug 28, 2025
12 months ago
Sep 5, 2025
11 months ago
1w newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Grok Code Fast 1 is available from xAI. Kimi K2-Thinking-0905 is available from DeepInfra, Novita, Fireworks.
Grok Code Fast 1
Kimi K2-Thinking-0905
Outputs Comparison
Judge for yourself.
Run your own prompts against Grok Code Fast 1 and Kimi K2-Thinking-0905 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Grok Code Fast 1 vs Kimi K2-Thinking-0905.