GPT-5.1 Codex

About GPT-5.1 Codex

GPT-5.1 Codex is a dedicated software development model from OpenAI built for multi-turn repository editing and test-driven cycles. It features specialized patch-application tooling and session compaction over a 400K context window.

Technical Specifications

Architecture specifications are undisclosed for proprietary models.

Resources

About GPT-5

OpenAI's latest generation of language models featuring advanced reasoning capabilities, extended context windows up to 400K tokens, and specialized variants for coding, general intelligence, and efficiency. GPT-5 series introduces improved thinking modes, superior performance across benchmarks, and variants optimized for different use cases from high-capacity Pro models to efficient Nano models. Features native multimodal understanding, enhanced mathematical reasoning, and state-of-the-art coding abilities through Codex variants.

Other GPT-5 Models

• GPT-5 Mini
• GPT-5.4
• GPT-5 Nano
• GPT-5.2 Codex
• GPT-5.1 Codex Mini
• GPT-5.1
• GPT-5.2
• GPT-5 Pro