OpenAI: GPT-5.1-Codex

OpenAI: GPT-5.1-Codex

openai · Released Nov 13, 2025
Intelligence #160 / 756
44.1 our score
Speed #39 / 333
196.0 tok/s
Input Price #601 / 779
$1.25 per 1M tokens
Output Price #656 / 779
$10.00 per 1M tokens
Context #197 / 779
400,000 tokens

Analysis Summary

OpenAI's GPT-5.1-Codex is a coding-focused multimodal model with a 400K context window, vision, tool use, and function calling. Its available intelligence result and product design support substantial codebase work, visual development tasks, and tool-driven engineering workflows over very large inputs.

The model is well suited to repository understanding, implementation, debugging, code review, and autonomous software agents. The record does not include a coding index or detailed coding benchmark results, so its comparative engineering reliability should be validated directly. Premium output pricing also argues for routing routine edits and low-risk generation to a cheaper model.

Use it for high-value engineering tasks where long context and integrated tools reduce operational friction. Treat it as a specialist coding deployment until broader benchmark evidence is available.

Assessed September 7, 2026

Editorial notes

GPT-5.1-Codex combines a 400K context, vision, tool use, and function calling with a coding-focused profile. Its premium pricing makes it best suited to high-value engineering and agent workflows rather than routine generation.

Rankings consider pricing, capabilities, benchmarks, and real-world applicability and are refreshed as new models launch. Feedback?

DFO Verdict

GPT-5.1-Codex combines a 400K context, vision, tool use, and function calling with a coding-focused profile. Its premium pricing makes it best suited to high-value engineering and agent workflows rather than routine generation.

#160 of 756 overall

How OpenAI: GPT-5.1-Codex compares

OpenAI: GPT-5.1-Codex ranks #105 of 438 AI models we track for overall intelligence. Its 400K-token context window is larger than 75% of the models we list. At $1.25 per million input tokens it is cheaper than 23% of comparable models.

Position in the field
Intelligence: smarter than 79% of models #160
Speed: faster than 88% of models #39
Price: cheaper than 23% of models #601
Context: larger than 75% of models #197
worst in fieldmedianbest in field
Price vs frontier peers · $ per 1M tokens
OpenAI: GPT-5.1-Codex $1.25 in $10.00 out
OpenAI: GPT-6 Astra $10.00 in $50.00 out
Anthropic: Claude Fable 5.1 $10.00 in $50.00 out
Claude Opus 5 $5.00 in $25.00 out

Dark bar = input · light bar = output, scaled to the priciest peer.

Context window vs peers · tokens
OpenAI: GPT-5.1-Codex 400K

1M tokens ≈ 8 full-length novels or ~2,500 pages of business documents in a single request.

Intelligence4Technical0Value6.5Content7.5
Performance profile

Strongest on business fit. The pulled-in technical corner is the trade-off, and if the shape matters more than the price, this is your model.

Compare shapes side-by-side →

Pricing

Token Type Cost per 1M tokens Cost per 1K tokens
Input $1.25 $0.001250
Output $10.00 $0.010000

What would OpenAI: GPT-5.1-Codex cost your business?

Pick the job that looks most like yours, then fine-tune with the sliders. Estimates update live.

A website chatbot handling around 100 customer conversations a day, a few short messages each.

3,000
One request is one message, email, draft or automation call.
1,200 tokens

$0/mo OpenAI: GPT-5.1-Codex

Full calculator with 779 models → Price Calculator

DFO AI AUTOMATION

These numbers get smaller with the right architecture.

We route routine calls to cheap models and save OpenAI: GPT-5.1-Codex for the hard ones. Most clients cut their estimate by 60-80%.

Talk to our team

About OpenAI: GPT-5.1-Codex

GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks..

Frequently asked questions about OpenAI: GPT-5.1-Codex

How much does OpenAI: GPT-5.1-Codex cost?

OpenAI: GPT-5.1-Codex costs $1.25 per million input tokens and $10.00 per million output tokens.

What is the context window of OpenAI: GPT-5.1-Codex?

OpenAI: GPT-5.1-Codex has a context window of 400,000 tokens (400K).

What can OpenAI: GPT-5.1-Codex do?

OpenAI: GPT-5.1-Codex supports image/vision input, tool use, and function calling.

Who created OpenAI: GPT-5.1-Codex?

OpenAI: GPT-5.1-Codex is developed by OpenAI and was released on November 13, 2025.

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