GPT-5.1
OpenAI's coding-focused GPT-5 refresh with configurable reasoning effort
GPT-5.1 is OpenAI’s update to GPT-5, released November 13, 2025 with an emphasis on coding and agentic tasks. It carries the same 400,000 token context window as GPT-5, with up to 128,000 tokens of output, and API pricing held at $1.25 per million input tokens and $10 per million output tokens, with cached input priced at $0.125 per million. The model exposes a reasoning-effort setting with none, low, medium, and high options, giving developers more control over how much internal deliberation a request gets than GPT-5’s automatic routing offered. OpenAI positioned it as a refinement rather than a new generation, shipped to close gaps competitors had opened up on coding benchmarks in the months since GPT-5’s August 2025 launch.