GPT-5.1-Codex-Max
coding modelOpenAI
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...
Key facts
| Made by | OpenAI |
|---|---|
| Type | coding model |
| Released | December 4, 2025 |
| Reads at once | 400,000 tokens |
| Price (API, per million tokens) | $1.25 in · $10 out |
| Input → output | text, image → text |
Questions about GPT-5.1-Codex-Max
Who makes GPT-5.1-Codex-Max?
GPT-5.1-Codex-Max is made by OpenAI.
When was GPT-5.1-Codex-Max released?
We first saw GPT-5.1-Codex-Max listed on December 4, 2025.
How much does GPT-5.1-Codex-Max cost?
Through OpenRouter it costs $1.25 per million input tokens and $10 per million output tokens. Prices change, so check the provider before you build on it.
How much text can GPT-5.1-Codex-Max read at once?
Up to 400,000 tokens, roughly 300K words.
More from OpenAI
Whisper-SmallOpenAI · voice and audio model
Sep 26, 2022released
Whisper-Large-V3OpenAI · voice and audio model
Nov 7, 2023released
whisperOpenAI · voice and audio model
Sep 26, 2022released
Whisper-TinyOpenAI · voice and audio model
Sep 26, 2022released
Openai-Agents-Pythonopenai · developer tool
Mar 11, 2025released
Whisper-MediumOpenAI · voice and audio model
Sep 26, 2022released
Other ai for coding
ECCaffaan-m · coding model
Jan 18, 2026released
Claude-Memthedotmack · coding model
Aug 31, 2025released
Taste-SkillLeonxlnx · coding model
Feb 19, 2026released
Archifytt-a1i · coding model
Apr 15, 2026released
Claude-Code-Best-Practiceshanraisshan · coding model
Oct 31, 2025released
Qwen3-CoderAlibaba (Qwen) · coding model
Jul 31, 2025released
Marketingskillscoreyhaines31 · coding model
Jan 15, 2026released
Agentswshobson · coding model
Jul 24, 2025released
Modelcast collects this page automatically from public sources (OpenRouter). Facts are copied from those sources, not written by the maker. Not affiliated with OpenAI.