GPT 5.1 Codex
LegacyPremiumPrevious-generation coding-optimized model for software engineering.
Strong at multi-file editing, test generation, and code review. Supports image inputs for UI and design work.
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GPT 5.1 Codex is somewhat expensive at $1.25/M tokens input and $10.00/M tokens output. Cached input reads are priced at $0.13/M tokens, making repeated context cheaper. The model supports vision/image input, extended reasoning, a 400K context window.
Benchmarks
This model hasn't been evaluated by Artificial Analysis yet. Benchmark scores will appear once they're published.
Specifications
Performance
Providers
Misc
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When was GPT 5.1 Codex released?
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GPT 5.1 Codex was released on November 13, 2025.
Who created GPT 5.1 Codex?
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GPT 5.1 Codex was created by OpenAI.
How much does GPT 5.1 Codex cost?
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GPT 5.1 Codex costs $1.25/M input tokens and $10.00/M output tokens.
What is GPT 5.1 Codex API pricing?
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The GPT 5.1 Codex API is priced at $1.25 per million input tokens and $10.00 per million output tokens. You can access GPT 5.1 Codex through idapt.app alongside 200+ other AI models in one workspace.
Is GPT 5.1 Codex a reasoning model?
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Yes, GPT 5.1 Codex is a reasoning model. It can think step-by-step through complex problems before providing an answer, often yielding better results on difficult tasks like math, coding, and multi-step logic.
Does GPT 5.1 Codex support image or vision input?
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Yes, GPT 5.1 Codex supports vision/image input. You can share images in your conversation and the model will analyze and respond based on their content.
Does GPT 5.1 Codex support audio?
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No, GPT 5.1 Codex does not support audio input.
What is the context window of GPT 5.1 Codex?
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GPT 5.1 Codex has a context window of 400K tokens, meaning it can process approximately 300,000 words of context at once.
Is GPT 5.1 Codex open source?
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GPT 5.1 Codex is a proprietary model developed by OpenAI. The model weights and training data are not publicly available.
What is GPT 5.1 Codex good at?
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Based on benchmark data, GPT 5.1 Codex excels at: visual analysis and image understanding. It is OpenAI's capable model suitable for a wide range of tasks.
Where can I use GPT 5.1 Codex?
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You can chat with GPT 5.1 Codex on idapt.app — no separate API key required. idapt is an AI workspace with 200+ models, agents, computers, and tasks. You can also access GPT 5.1 Codex through OpenAI's own API or platform.