GPT-5.1-Codex-Max
GPT-5.1-Codex-Max sits in the frontier tier — built for high-capability reasoning, tool use, and long-form output where capability outweighs cost. Available via OpenAI. 400,000-token context. Mid-tier pricing.
GPT-5.1-Codex-Max is a multimodal AI model from OpenAI. It costs $1.250 per million input tokens and $10.000 per million output tokens (blended $3.875/M), with a 400,000-token context window.
- Strong general reasoning
- Tool use & function calling
- Long-form writing
- Production-grade reliability
- Multimodal: handles images alongside text
- Production assistants
- Long-document analysis
- Multi-step agent workflows
- Engineering copilots
Benchmarks
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How much does GPT-5.1-Codex-Max cost?
GPT-5.1-Codex-Max costs $1.250 per million input tokens and $10.000 per million output tokens, for a blended reference rate of $3.875 per million tokens.
What is GPT-5.1-Codex-Max's context window?
GPT-5.1-Codex-Max supports up to 400,000 tokens of context in a single request.
What is GPT-5.1-Codex-Max best for?
GPT-5.1-Codex-Max is well suited to Strong general reasoning, Tool use & function calling and Long-form writing.
Who makes GPT-5.1-Codex-Max?
GPT-5.1-Codex-Max is developed and served by OpenAI.