OpenAI: GPT-5.1-Codex
Analysis Summary
OpenAI: GPT-5.1-Codex sits in the Professional tier on our leaderboard, ranked #39 of 525 published models on overall intelligence. At $1.25 input and $10.00 output per 1M tokens, it is among the most expensive on the market. It offers a generous context window for extended reasoning and code review and supports tool use, function calling, vision, and reasoning.
Editorial notes
OpenAI's GPT-5.1-Codex delivers strong reasoning and solid coding performance with vision support and a 400K context window, making it a capable choice for technical business tasks, though it sits a step below the top-tier GPT-5.1 flagship in overall intelligence.
Assessed April 23, 2026
Rankings consider pricing, capabilities, benchmarks, and real-world applicability and are refreshed as new models launch. Feedback?
Performance Profile
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..
Capabilities
Performance Indices
Source: Artificial Analysis
Benchmark Scores
Intelligence
Technical
Content
Benchmark data from Artificial Analysis and Hugging Face
How does OpenAI: GPT-5.1-Codex stack up?
Compare side-by-side with other professional models.
Model Information
| OpenRouter ID |
openai/gpt-5.1-codex
|
| Provider | openai |
| Release Date | November 13, 2025 |
| Context Length | 400,000 tokens |
| Max Completion | 128,000 tokens |
| Status | Active |
Pricing
| Token Type | Cost per 1M tokens | Cost per 1K tokens |
|---|---|---|
| Input | $1.25 | $0.001250 |
| Output | $10.00 | $0.010000 |
Live Performance
Live endpoint metrics ā refreshed every 30 minutes.
