Article · Wikipedia archive · Last revised Jun 13, 2026

GPT-5.3-Codex

GPT-5.3-Codex is a large language model (LLM) announced and released by OpenAI on February 5, 2026.

Last revised
Jun 13, 2026
Read time
≈ 1 min
Length
256 w
Citations
6
Source
Wikipedia ↗

GPT-5.3-Codex (Generative Pre-trained Transformer 5.3 Codex) is a large language model (LLM) announced and released by OpenAI on February 5, 2026.1

It is made as a competitor to Claude's Opus 4.6, focusing on code generation, speed and the ability to search repositories, run terminal commands and at the same time, debug code. In technical benchmarks, it is reported that GPT-5.3 Codex is 25% faster than Opus 4.6.2

GPT-5.3 Codex is available in the Codex app and on the web; access via API is also planned.3

According to OpenAI, GPT-5.3-Codex is the company's "first model that was instrumental in creating itself."45

On February 12, 2026, GPT-5.3-Codex-Spark was released in a research preview, which is a smaller version of GPT-5.3-Codex which supports text-only input. As of February 2026, GPT-5.3-Codex is only available for ChatGPT Pro ($200/month) subscribers.6

References

References

  1. Axon, Samuel (February 5, 2026). "With GPT-5.3-Codex, OpenAI pitches Codex for more than just writing code". Ars Technica. Retrieved April 3, 2026.
  2. "GPT-5.3 Codex: From Coding Assistant to General Work Agent". www.datacamp.com. Retrieved March 27, 2026.
  3. "OpenAI's new GPT-5.3-Codex is 25% faster and goes way beyond coding now - what's new". ZDNET. Retrieved April 3, 2026.
  4. Werth, Timothy Beck (February 5, 2026). "OpenAI: New coding model GPT-5.3-Codex helped build itself". Mashable. Retrieved April 3, 2026.
  5. Peckham, James; Albanesius, Chloe (February 6, 2026). "OpenAI's Newest GPT Model Helped to Build Itself". PCMag. Retrieved April 8, 2026.
  6. Viswanathan, Pradeep (February 12, 2026). "OpenAI introduces GPT‑5.3‑Codex‑Spark, an ultra-fast coding model powered by Cerebras". Neowin. Retrieved April 8, 2026.
External links