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OpenAIProprietary
GPT-5 Codex
GPT-5 Codex is a programming-specialized AI model developed by OpenAI. It features a vast context window of 400K and is optimized for processing large codebases.
Parameters
Undisclosed
Context Window
400K
License
Proprietary
Release Date
2025-09-15
API Pricing
API pricing for this model is not yet available
Strengths
- ・Very long context retention of 400K
- ・Advanced code generation and analysis
- ・Latest optimizations by OpenAI
Weaknesses
- ・Opacity due to closed-source
- ・Constraints from license restrictions
- ・Lack of external model details
Use Cases
- ・Code analysis for large projects
- ・Advanced automated programming implementation
- ・Complex bug fixing and refactoring
Deep Analysis
Release Date
August 2025
Context Window
400K tokens
Focus
Coding and agentic tasks
Strengths
- ・Specialized for coding
- ・400K context
- ・Part of Codex ecosystem
Weaknesses
- ・Superseded by newer Codex variants
- ・Limited public benchmarks
Competitor Comparison
| Model | SWE | Price |
|---|---|---|
| GPT-5 | 74.9% | $1.25/$10 |
| GPT-5.3 Codex | 56.8% | $1.75/$14 |
Sources
Analysis generated: 2026-05-24