GPT‑5-Codex
No estimate
No hardware requirements for this model
The weights for this model have not been published, so it cannot be downloaded or run on your own hardware at any size. It is reachable only through its provider, and no graphics card changes that.
On record
Full specification
Everything on record for this model. Most of it describes how it was trained rather than how it runs — useful context for judging how much work went into it, and how it compares with models built at a different scale.
Origin
Who built this model, where, and when it was published.
- Organisation
- OpenAI
- Organisation type
- Industry
- Country
- United States of America
- Published
- 15 September 2025
What it does
The problem areas the model was built for. A model can carry several of each.
- Domain
- Language
- Task
- Code generation, System control
- Base model
- GPT-5
Size
How large the model is and how much data it was trained on. Parameters are the figure that decides whether it fits on a given graphics card.
- Training data
- tokens
Availability
Whether you can obtain the model and run it on your own hardware, which is what decides if any of the graphics-card figures on this page apply.
- Weights
- Closed — provider access only
- Model access
- API access
- Training code
- Unreleased
How it is classified
Labels the source dataset applies when tracking notable models, and how confident it is in the entry.
- Record confidence
- Unknown
Sources
Where this record came from and when it was last checked.
- Reference
- Introducing upgrades to Codex
- Last updated
- 6 March 2026
What the numbers mean
Where it came from
GPT‑5-Codex was published by OpenAI, in the country recorded as United States of America, during September 2025. The category the publisher falls under is industry.
It works in the domain of Language, and is recorded as performing the task of code generation, System control.
Rather than being trained from scratch, it is derived from GPT-5. That is why it shares the base model's general shape and size.
Because the weights are not available, none of the hardware figures elsewhere on this site apply to it.
Answers
GPT‑5-Codex — common questions
GPT‑5-Codex— when was it released?
It was published in September 2025.
GPT‑5-Codex— what is it used for?
It works in the domain of Language, and is recorded as handling the task of code generation, System control. Models frequently carry more than one of each, and the tags describe purpose rather than capability limits.
GPT‑5-Codex— what GPU do I need to run it?
None. This is a closed model — its weights were never published, so it cannot be downloaded or run on your own hardware at any price. It is reachable only through its provider.
GPT‑5-Codex— is it open source?
No. Its weights have not been published, so it exists only as a service controlled by its owner.
GPT‑5-Codex— how many parameters does it have?
No parameter count has been published for it, which is why no memory or speed figure appears on this page.
GPT‑5-Codex— who created it?
It was published by OpenAI, based in United States of America, an organisation categorised as industry.
The other direction
Looking at it from the other side?
This page starts from the model. If you already own a card and want to know everything it will run, start from the hardware instead.