OpenAI
GPT-5.1 Codex Max
Coding-optimized GPT model for repository edits, reviews, and agentic software work
Model facts
- Context window
- 4K tokens
- Maximum output
- 128K tokens
- Cheapest paid input
- $1.1 per 1M tokens
- Cheapest paid output
- $9 per 1M tokens
- Open weights
- no
- Providers
- 14
Capabilities and modalities
reasoning, tool calling, structured output, attachments, temperature control, text, image, pdf.
Observed price history
- 2026-08-24: $1.1 input / $9 output per 1M tokens
API providers
- Poe — model id openai/gpt-5.1-codex-max; $1.1 input / $9 output per 1M tokens; provider documentation
- Jiekou.AI — model id gpt-5.1-codex-max; $1.12 input / $9 output per 1M tokens; provider documentation
- Abacus — model id gpt-5.1-codex-max; $1.25 input / $10 output per 1M tokens; provider documentation
- Azure — model id gpt-5.1-codex-max; $1.25 input / $10 output per 1M tokens; provider documentation
- DigitalOcean — model id openai-gpt-5.1-codex-max; $1.25 input / $10 output per 1M tokens; provider documentation
- Eden AI — model id azure/gpt-5.1-codex-max; $1.25 input / $10 output per 1M tokens; provider documentation
- Kilo Gateway — model id openai/gpt-5.1-codex-max; $1.25 input / $10 output per 1M tokens; provider documentation
- Ofox — model id openai/gpt-5.1-codex-max; $1.25 input / $10 output per 1M tokens; provider documentation
- OpenCode Zen — model id gpt-5.1-codex-max; $1.25 input / $10 output per 1M tokens; provider documentation
- OpenRouter — model id openai/gpt-5.1-codex-max; $1.25 input / $10 output per 1M tokens; provider documentation
- Vercel AI Gateway — model id openai/gpt-5.1-codex-max; $1.25 input / $10 output per 1M tokens; provider documentation
- Vivgrid — model id gpt-5.1-codex-max; $1.25 input / $10 output per 1M tokens; provider documentation
- NanoGPT — model id openai/gpt-5.1-codex-max; $2.5 input / $20 output per 1M tokens; provider documentation
- Arena — model id gpt-5.1-codex-max; not published input / not published output per 1M tokens; provider documentation