Kimi K2.5 vs GPT-5.1-Codex-Max: side-by-side summary

Kimi K2.5 and GPT-5.1-Codex-Max are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.

Kimi K2.5, from moonshotai, has a 262,144-token context window and is priced at $0.45/M tokens input, $2.25/M tokens output on OpenRouter.

GPT-5.1-Codex-Max, from OpenAI, has a 400,000-token context window and is priced at $1.25/M tokens input, $10/M tokens output on OpenRouter.

Context window

• Kimi K2.5: 262,144 tokens
• GPT-5.1-Codex-Max: 400,000 tokens

Price

• Kimi K2.5: $0.45/M tokens input, $2.25/M tokens output
• GPT-5.1-Codex-Max: $1.25/M tokens input, $10/M tokens output

Provided by

• Kimi K2.5: moonshotai
• GPT-5.1-Codex-Max: OpenAI