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GPT-5.3-Codex
OpenAI · GPT-5
OpenAI released GPT-5.3-Codex on February 5, 2026.
GPT-5.3-Codex is the OpenAI coding agent model introduced on February 5, 2026. It combines the coding performance of GPT-5.2-Codex with the reasoning and professional knowledge of GPT-5.2 in one model, aimed at the whole software lifecycle and at general computer-based knowledge work. It launched for paid ChatGPT plans everywhere Codex runs (the app, CLI, IDE extension and web), running 25% faster for Codex users, and reached the Responses API as gpt-5.3-codex on February 24, 2026. OpenAI classified it as the first model with High capability for cybersecurity under its Preparedness Framework.
GPT-5.3-Codex at a glance
- Released
- API model id
gpt-5.3-codex- Available on
- CodexOpenAI API
- Announcement
- openai.com
What changed
OpenAI's published results against GPT-5.2-Codex (both at xhigh effort): Terminal-Bench 2.0 77.3% vs 64.0%, OSWorld-Verified 64.7% vs 38.2%, and SWE-Bench Pro (Public) 56.8% vs 56.4%.
It is also the first OpenAI model trained directly to identify software vulnerabilities, so requests flagged as elevated cyber risk can be routed to GPT-5.2.
New to model names and version numbers? Read how AI labs version their models.
GPT-5.3-Codex release timeline
The launch and every later OpenAI release that mentions GPT-5.3-Codex, oldest first.
- Introducing GPT-5.3-Codex
OpenAI launched GPT-5.3-Codex as its most capable agentic coding model yet, combining Codex and GPT-5 training stacks into a faster model for long-running work on real projects.
Source: OpenAI - GPT-5.3-Codex in Cursor and VS Code
GPT-5.3-Codex is available natively in Cursor and VS Code, with API access starting for a small set of customers in a phased release. It is the first model treated as a high security capability under the Preparedness Framework.
Source: Codex Changelog - Introducing GPT-5.3-Codex-Spark
OpenAI shipped GPT-5.3-Codex-Spark as a fast research preview for real-time coding in the Codex app, CLI, and VS Code extension.
Source: OpenAI
GPT-5.3-Codex FAQ
When was GPT-5.3-Codex released?
OpenAI released GPT-5.3-Codex on February 5, 2026. The launch entry below links to the official announcement.
Where is GPT-5.3-Codex available?
GPT-5.3-Codex is available on Codex and OpenAI API. Later availability changes are listed under follow-up releases on this page.
What is the GPT-5.3-Codex API model id?
Use gpt-5.3-codex in OpenAI's API.
Other OpenAI models
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