GPT-5.3 Codex
Full SDLC agent: debug, terminal, PRDs, tests
- Vendor
- OpenAI
- License
- closed
- Released
- 2026-03
- Parameters
- Undisclosed
- Context window
- 400k tokens
Capabilities
GPT-5.3 Codex supports vision (image input), tool use, extended reasoning and computer use, with a 400k-token context window.
- Vision — image input
- Audio — audio input (not confirmed)
- Tools — function calling / tool use
- Reasoning — extended thinking
- Computer use — desktop / browser control
Benchmarks
| SWE-Bench Verified | 80% |
|---|---|
| SWE-Bench Pro | 56.8% |
| Terminal-Bench | 77.3% |
| Reasoning composite | 91 / 100 |
The reasoning composite is a directional 0–100 score aggregated across public reasoning evals — comparable within this matrix, not an official vendor number.
Pricing
$10/M input tokens.