OpenAI

GPT-5.3 Codex Spark

Announced Feb 12, 2026

Coding with very low delay

What could it do?

OpenAI previewed a smaller model optimized for fast coding responses on Cerebras hardware.

Prioritized interactive speed.

WHY IT MATTERED

Reduced waiting during iterative coding.

Research preview; initially text only with a 128K context window.

Sources checked Oct 7, 2026

Release facts were checked against the sources below. Performance claims belong to the developers; we have not independently tested these models.

No comparable ECI score is available for this release in our source snapshot. Missing scores are never estimated.