Due to leave the API on 1 April 2027, so coding-agent builders should plan a move to GPT-6 Sol.
Kenning's take
What it does
GPT-5.3-Codex is an OpenAI model tuned for agentic software work in Codex and similar tools. It launched for paid ChatGPT plans in Codex in February 2026 and reached the API later that month. It was dropped from the Codex picker for ChatGPT sign-ins in May 2026 and OpenAI plans to remove it from the API on 1 April 2027, recommending GPT-6 Sol instead.
- Tuned for agentic coding
- 400K-token context window
- Low to xhigh reasoning effort
- Text and image input
Who it suits. Developers running coding agents who have not yet moved to newer models.
Key facts
- Category
- AI models
- Made by
- OpenAI
- Based in
- United States
- Released
- 5 February 2026
- How to get it
- OpenAI API (model gpt-5.3-codex) until 1 April 2027; no longer selectable in Codex with ChatGPT sign-in
- Works on
- API
- In the UK
- Yes
- API price
- $1.75 per million input tokens, $14 per million output
FAQ
When was GPT-5.3-Codex released?
In Codex on 5 February 2026; in the API on 24 February 2026.
Is GPT-5.3-Codex being retired?
Yes, OpenAI plans to remove it from the API on 1 April 2027 and recommends GPT-6 Sol.
Facts from the maker's own pages and the sources listed. Checked 2026-10-11.
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