Models / openai / GPT-5.3 Codex

GPT-5.3 Codex

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openaillm

The latest Codex iteration, featuring improved context handling and advanced code analysis capabilities.

textcode-generationfunction-callingstreamingjson-modetool-usereasoningvisionprompt-caching
Specs
Context & limits
272K
context window
128K
max output
Lifecycle
Dates
released2026-03-01
knowledge cutoff2025-10-01
Resources