Compare GPT-5.1-Codex-Mini from OpenAI and Step3 from stepfun-ai 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-Mini and Step3 are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
GPT-5.1-Codex-Mini, from OpenAI, has a 400,000-token context window and is priced at $0.25/M tokens input, $2/M tokens output on OpenRouter.
Step3, from stepfun-ai, has a 65,536-token context window and is priced by the provider serving it on OpenRouter.