OpenAI: GPT-5.1-Codex
openai/gpt-5.1-codex
68th smartest of 183ReasoningToolsJSONVision
Intelligence
34.7
68th of 183
Design Elo
1202
Data Viz
Speed
—
tokens/sec
Latency
—
first token
Input price
$1.25
249th cheapest
Context
400K
128K max out
How it compares
Smarter than63%
of all ranked models
Cheaper than26%
of all ranked models
Overview
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....
Benchmarks
independent · Artificial Analysis & Design ArenaArtificial Analysis83th percentile
Intelligence Index
34.7
GPQA Diamond
86%
Humanity's Last Exam
23%
SciCode
40%
Tau²-Bench (agentic)
83%
Design Arena · Elo71 tournaments
Data Viz
1202
Website
1186
Providers & pricing (1)
| Provider | In $/M | Out $/M | Context | Uptime |
|---|---|---|---|---|
| Azurecache | $1.25 | $10.00 | 400K | 100% |
Specifications
Context window400K
Max output128K
Knowledge cutoff—
Input modalitiestext, image
Output modalitiestext
Prompt cachingSupported
Cache read price$0.130/M
ModeratedNo
GPT-5.1-Codex FAQ
How much does GPT-5.1-Codex cost?
GPT-5.1-Codex costs $1.25 per million input tokens and $10.00 per million output tokens via OpenRouter, making it 249th cheapest of 335 paid models.
How smart is GPT-5.1-Codex?
GPT-5.1-Codex scores 34.7 on the Artificial Analysis Intelligence Index, ranking 68th of 183 benchmarked models, with a GPQA Diamond score of 86%.
What is GPT-5.1-Codex's context window?
GPT-5.1-Codex supports a 400K-token context window and can output up to 128K tokens. It accepts text, image input.