GPT-5.1-Codex
OpenAI · Multimodal · Released Nov 2025
GPT-5.1-Codex is OpenAI's specialized model for software engineering tasks, built on the GPT-5.1 architecture with a 400k token context window.
- Strengths
- The model excels at code generation, debugging, and software engineering workflows with strong reasoning capabilities across programming languages and frameworks.
- Best for
- Building, refactoring, and analyzing code across large codebases and complex engineering tasks that benefit from extended context.
- Limitations
- This model has been superseded by GPT-5.2 for general reasoning tasks, and GPT-5.1-Codex-Max offers expanded capacity for demanding software engineering projects.
Input / 1M
$1.25
Output / 1M
$10.00
Cached input / 1M
$0.13
Context window
400K
Price history
Input (solid)Output (dashed)
Price change
- 30d
- in decreased 0.0% out decreased 0.0%
- 90d
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- 1y
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- Since launch
- in decreased 0.0% out decreased 0.0%
Snapshots
| Effective | Input | Output | Cached in | Note | Source |
|---|---|---|---|---|---|
| 26 Jul 2026 | $1.25 | $10.00 | $0.13 | Imported from OpenRouter | openrouter.ai |
| 15 Jul 2026 | $1.25 | $10.00 | $0.125 | Imported from OpenRouter | openrouter.ai |
| 11 Jun 2026 | $1.25 | $10.00 | $0.13 | Imported from OpenRouter | openrouter.ai |