Cracked AI Engineering

Claude Sonnet 4.5 vs Kimi K2

Claude Sonnet 4.5 offers 1.0M tokens context vs 131K tokens, Kimi K2 is more cost-effective, Claude Sonnet 4.5 includes advanced reasoning. Compare full specs, pricing, and choose the best model for your use case.

Quick Overview

Claude Sonnet 4.5

OpenRouter

1.0M tokens context • $3.00 / $15.00 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
Claude Sonnet 4.5
Kimi K2
Provider
OpenRouter
OpenRouter
Context Window
1.0M tokens
131K tokens
Max Output Tokens
64K tokens
33K tokens
Input Pricing (per 1M tokens)
$3.00
$0.55
Output Pricing (per 1M tokens)
$15.00
$2.20
Release Date
Sep 2025
Jul 2025

Capabilities

Capability
Claude Sonnet 4.5
Kimi K2
Text Generation
Vision
Function Calling
Advanced Reasoning
File Attachments

Which Model Should You Choose?

Choose Claude Sonnet 4.5 if:

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

Choose Kimi K2 if:

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