OpenAI: GPT-5.1-Codex-Max
OpenAI's GPT-5.1-Codex-Max is a variant of the GPT-5.1 family with no independent benchmark data of its own, so it cannot inherit the parent model's scores. It offers a large 400K context window, vision, and strong tool use capabilities from a trusted provider, but must be scored conservatively without direct performance evidence.
Assessment date: March 12, 2026
Our methodology takes into account a range of factors including pricing, functionality, capabilities, benchmark performance, and real-world applicability. Rankings are reviewed and updated regularly as new models are released. Issues with our rankings? Contact us
GPT-5.1-Codex-Max is OpenAI’s latest agentic coding model, designed for long-running, high-context software development tasks. It is based on an updated version of the 5.1 reasoning stack and trained on agentic workflows spanning software engineering, mathematics, and research. GPT-5.1-Codex-Max delivers faster performance, improved reasoning, and higher token efficiency across the development lifecycle.
Capabilities
Architecture
| Modality | Text + Image → Text |
| Tokenizer | GPT |
Model Information
Pricing
| Token Type | Cost per 1M tokens | Cost per 1K tokens |
|---|---|---|
| Input | $1.25 | $0.001250 |
| Output | $10.00 | $0.010000 |
Live Performance
Live endpoint metrics — refreshed every 30 minutes.
