GPT-5.3 Codex
gpt-codex
Coding-optimized GPT model for repository edits, reviews, and agentic software work
ReasoningTool CallingAttachmentsStructured Output
Context Window
400K
Max Output
128K
Temperature
No
Open Weights
No
Knowledge Cutoff
2025-08-31
Released
2026-02-05
Last Updated
2026-02-05
Modalities
Input:TextImagePDF
→Output:Text
Benchmarks
| Benchmark | Score | Metric | Harness |
|---|---|---|---|
| SWE-Atlas Codebase QnA | 32.6 | score | Codex |
| SWE-Atlas Refactoring | 42.38 | score | Codex |
| SWE-Atlas Test Writing | 38.98 | score | Codex |
Available Providers (10)
| Provider | Input /1M | Output /1M | Cache Read /1M | Cache Write /1M | Reasoning | Status |
|---|---|---|---|---|---|---|
 Requesty | Rp 31.559 | Rp 252.472 | Rp 3.156 | — | effort, budget_tokens | — |
 Vercel AI Gateway | Rp 31.559 | Rp 252.472 | Rp 3.156 | — | effort | — |
 ZenMux | Rp 31.559 | Rp 252.472 | — | — | effort | — |
 OrcaRouter | Rp 31.559 | Rp 252.472 | Rp 3.156 | — | ✓ | — |
 Cloudflare AI Gateway | Rp 31.559 | Rp 252.472 | Rp 3.156 | — | effort | — |
 Poe | Rp 28.854 | Rp 234.439 | Rp 2.886 | — | effort | — |
 Kilo Gateway | Rp 31.559 | Rp 252.472 | — | — | effort | — |
 OpenRouter | Rp 31.559 | Rp 252.472 | Rp 3.156 | — | effort | — |
 FastRouter | Rp 31.559 | Rp 252.472 | — | — | effort | — |
 NanoGPT | Rp 31.559 | Rp 252.472 | Rp 3.156 | — | effort | — |