GPT‑5.3‑Codex‑Spark5.3
An ultra-fast model for real-time coding in Codex
GPT‑5.3‑Codex‑Spark is a real‑time coding model offered as a research preview for ChatGPT Pro users. It provides a large context window and rapid token generation, allowing interactive collaboration where prompts can be interrupted, redirected, and refined with immediate feedback. Optimized for speed, the model focuses on targeted edits and code refinement, running tests only when requested.