GPT-5.2-Codex

A coding-specialized model from OpenAI's GPT-5.2 generation with a 400k token context window, released in December 2025 as a variant optimized for software engineering tasks.

Strengths

Handles large codebases and multi-file contexts without truncation, maintaining awareness of extended code and documentation within its wide context window.

Best for

Software projects that require reasoning across substantial code repositories, long-form documentation, or complex multi-step development workflows.

Limitations

Superseded by GPT-5.4 Pro and the GPT-5.4 series released in March 2026, which offer improved general-purpose and coding capabilities; use GPT-5.4 Pro for current frontier reasoning and coding work.