Codex Models by OpenAI
OpenAIProprietary
5 models2021–2026Up to 400K ctxFrom $1.75/1M input
About
OpenAI coding models optimized for agentic software engineering in Codex and similar developer environments, including GPT-5.3-Codex.
Specifications(5 models)
| Model | Released | Context | Vision | Reasoning | Fn Calling | Tool Use | Structured Outputs | Code Exec |
|---|---|---|---|---|---|---|---|---|
| GPT-5.3-Codex | 2026-02 | 400K | Yes | Yes | Yes | Yes | Yes | Yes |
Available From(2 providers)
Pricing
| Model | Provider | Input / 1M | Output / 1M | Type |
|---|---|---|---|---|
| GPT-5.3-Codex | OpenRouter | $1.75 | $14 | Serverless |
| GPT-5.3-Codex | OpenAI API | $1.75 | $14 | Serverless |
Frequently Asked Questions
- What is Codex used for?
- Codex is used for code, vision and multimodal work, and reasoning. The family description and listed model capabilities point to those workloads as the best fit.
- How does Codex compare to GPT Realtime 2?
- Codex by OpenAI is strongest where you need code, while GPT Realtime 2 by OpenAI is the closest related family to check for translation. Codex has 5 listed variants and reaches up to 400K context, while GPT Realtime 2 reaches up to 131K context, so compare the specs and pricing tables before choosing a production model.
- Which Codex model should I use?
- For the lowest listed input price, start with GPT-5.3-Codex through OpenRouter at $1.75/1M input tokens. For the most capable/latest local choice, evaluate GPT-5.3-Codex with 400K context and reasoning, tool use, function calling, structured outputs, and multimodal inputs.
