Back to Models
OpenAIProprietary
GPT-5.3 Codex
GPT-5.3 Codex is a programming-specialized foundation model developed by OpenAI. Equipped with a very long context window of 400K, it is suitable for processing large codebases.
Parameters
Undisclosed
Context Window
400K
License
Proprietary
Release Date
2026-02-05
API Pricing
API pricing for this model is not yet available
Strengths
- ・Advanced coding capabilities
- ・400K long-context understanding
- ・Optimized by OpenAI
Weaknesses
- ・Non-open license
- ・Undisclosed source code
- ・Commercial use restrictions
Use Cases
- ・Large code analysis
- ・Complex program development
- ・Efficient code generation
Deep Analysis
Release Date
February 5, 2026
Terminal-Bench
77.3%
SWE-bench
56.8%
GPQA
81%
AIME 2025
94%
Context Window
400K tokens
Pricing
$1.75 / $14.00 per 1M tokens
Strengths
- ・Top-tier Terminal-Bench (77.3%)
- ・Fast throughput (350-1500 tok/s)
- ・1/7th cost of Claude Opus 4.6
Weaknesses
- ・SWE-bench Verified (56.8%) lower than GPT-5.2
Competitor Comparison
| Model | Arena | SWE | Price |
|---|---|---|---|
| GPT-5.4 | 1467 | ~80% | $2.50/$15 |
| Claude Opus 4.6 | $15/$75 |
Sources
Analysis generated: 2026-05-24