Cracked AI Engineering

GPT-5 Codex vs Kimi K2

GPT-5 Codex offers 400K tokens context vs 131K tokens, Kimi K2 is more cost-effective, GPT-5 Codex includes advanced reasoning. Compare full specs, pricing, and choose the best model for your use case.

Quick Overview

GPT-5 Codex

OpenRouter

400K tokens context • $1.25 / $10.00 per 1M tokens

View full specifications →

Kimi K2

OpenRouter

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

View full specifications →

Detailed Comparison

Specification
GPT-5 Codex
Kimi K2
Provider
OpenRouter
OpenRouter
Context Window
400K tokens
131K tokens
Max Output Tokens
128K tokens
33K tokens
Input Pricing (per 1M tokens)
$1.25
$0.55
Output Pricing (per 1M tokens)
$10.00
$2.20
Release Date
Sep 2025
Jul 2025

Capabilities

Capability
GPT-5 Codex
Kimi K2
Text Generation
Vision
Function Calling
Advanced Reasoning
File Attachments

Which Model Should You Choose?

Choose GPT-5 Codex if:

  • • You need a larger context window
  • • You need advanced reasoning

Choose Kimi K2 if:

  • • Cost efficiency is a priority
  • • You prefer open weights