Cracked AI Engineering

Grok 4 Fast vs Kimi K2

Grok 4 Fast offers 2.0M tokens context vs 131K tokens, Grok 4 Fast includes advanced reasoning, Grok 4 Fast supports vision. Compare full specs, pricing, and choose the best model for your use case.

Quick Overview

Grok 4 Fast

OpenRouter

2.0M tokens context • $0.20 / $0.50 per 1M tokens

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Kimi K2

OpenRouter

131K tokens context • $0.55 / $2.20 per 1M tokens

View full specifications →

Detailed Comparison

Specification
Grok 4 Fast
Kimi K2
Provider
OpenRouter
OpenRouter
Context Window
2.0M tokens
131K tokens
Max Output Tokens
30K tokens
33K tokens
Input Pricing (per 1M tokens)
$0.20
$0.55
Output Pricing (per 1M tokens)
$0.50
$2.20
Release Date
Aug 2025
Jul 2025

Capabilities

Capability
Grok 4 Fast
Kimi K2
Text Generation
Vision
Function Calling
Advanced Reasoning

Which Model Should You Choose?

Choose Grok 4 Fast if:

  • • You need a larger context window
  • • Cost efficiency is a priority
  • • You need advanced reasoning

Choose Kimi K2 if:

  • • You prefer open weights