Overview
GPT-5.1-Codex-Max is OpenAI’s latest agentic coding model, designed for long-running, high-context software development tasks.
GPT-5.1-Codex-Max is available in OmnyChat. 400,000 token context window. Image input. Reasoning mode. Tool calling.
Key capabilities
- 400,000 token context window
- Image input
- Reasoning mode
- Tool calling
Using this model
In OmnyChat
Use GPT-5.1-Codex-Max in OmnyChat and compare its results with other language models on the same task.
Best for: Chat and comparing answers on your own prompts.
Frequently asked questions
How do I use GPT-5.1-Codex-Max?
Open chat in OmnyChat and select GPT-5.1-Codex-Max. Model access and usage depend on your plan.
What does GPT-5.1-Codex-Max support in OmnyChat?
400,000 token context window. Image input. Reasoning mode. Tool calling.