Introducing GPT-5.3-Codex-Spark

OpenAI unveiled GPT-5.3-Codex-Spark, a smaller model built for real-time coding.

It is being offered as a research preview for ChatGPT Pro users on Cerebras hardware.

OpenAI also rolled out latency improvements, including WebSocket-based streaming, to speed up responses.

The launch targets interactive developer workflows and highlights the push for lower-latency AI infrastructure.