GPT-5.3 Codex
Parameters
Undisclosed
Context Length
128K
Modality
Text
Architecture
Undisclosed
License
Proprietary
Release Date
15 Jan 2026
Knowledge Cutoff
-
API Pricing (per 1M)
Input: $1.75 · Output: $14.00
Evaluation Benchmarks
Rank
#46
| Benchmark | Score | Rank |
|---|---|---|
Web Development | 1409 | 66 |
Intelligence Index | max 0.33 | 68 |
Rankings
Overall Rank
#46
Coding Rank
#88
About GPT-5.3 Codex
GPT-5.3 Codex High is OpenAI's premier coding model optimized for professional software development. Features state-of-the-art code generation, debugging, and architectural reasoning across 80+ programming languages. Excels at complex refactoring, system design, and understanding large codebases. Trained with enhanced focus on modern development practices, security patterns, and software engineering best practices. Ideal for advanced development workflows, code review, and architectural planning.
Technical Specifications
Architecture specifications are undisclosed for proprietary models.
Resources
About GPT-5.3
OpenAI's GPT-5.3 series represents specialized frontier models with a focus on coding excellence. The Codex variants feature enhanced programming capabilities, deeper understanding of software architecture, and superior performance on coding benchmarks. Designed for professional software development with advanced code generation, debugging, and refactoring abilities.