Compare GPT-5.1-Codex-Max from OpenAI and Grok 4.1 Fast from SpaceXAI on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the OpenRouter API.
GPT-5.1-Codex-Max and Grok 4.1 Fast are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
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.
Grok 4.1 Fast, from SpaceXAI, has a 2,000,000-token context window and is priced by the provider serving it on OpenRouter.