Grok Code Fast 1 vs Kimi K2.8 Preview
Comparing Grok Code Fast 1 and Kimi K2.8 Preview across benchmarks, pricing, and capabilities.
xAI · Moonshot AI · Updated for 2026
Which is better?
Grok Code Fast 1 and Kimi K2.8 Preview trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.
Kimi K2.8 Preview also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Grok Code Fast 1
- you want predictable pricing at $0.20/M input and $1.50/M output
Choose Kimi K2.8 Preview
- you process long inputs — it offers a 1,048,576 token context window
- you want the most recent training data — it shipped Sep 2026
At a glance
The differences that matter most.
Individual benchmarks
1 reported for Grok Code Fast 1 · 0 for Kimi K2.8 Preview
Grok Code Fast 1 and Kimi K2.8 Previewdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Human preference
Blind head-to-head votes and playground preference scores
Context Window
Maximum input and output token capacity
Kimi K2.8 Preview accepts 1,048,576 input tokens compared to Grok Code Fast 1's 256,000 tokens. Only Grok Code Fast 1 specifies output context (10,000 tokens).
Input capabilities
Documented input modalities across available providers
Kimi K2.8 Preview supports multimodal inputs, whereas Grok Code Fast 1 does not.
Kimi K2.8 Preview can handle both text and other forms of data like images, making it suitable for multimodal applications.
Grok Code Fast 1
Kimi K2.8 Preview
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Grok Code Fast 1 was released on 2025-08-28, while Kimi K2.8 Preview was released on 2026-09-11.
Kimi K2.8 Preview is 13 months newer than Grok Code Fast 1.
Aug 28, 2025
1.1 years ago
Sep 11, 2026
1 weeks ago
1.0yr 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 K2.8 Preview is available from Moonshot AI.
Grok Code Fast 1
Kimi K2.8 Preview
Outputs Comparison
Judge for yourself.
Run your own prompts against Grok Code Fast 1 and Kimi K2.8 Preview side-by-side, then vote on the output you prefer.
FAQ
Common questions about Grok Code Fast 1 vs Kimi K2.8 Preview.