GPT-5.1 Codex Mini by OpenAI demonstrates strong general intelligence, solid coding performance, fast output speed, competitive pricing. View detailed benchmark data including scores across coding, math, reasoning, speed, and cost metrics.
Specifications last checked against the provider on . Benchmark scores carry their own source, linked beside each number.
General Benchmarks
Massive Multitask Language Understanding professional benchmark
HuggingFace LeaderboardHuman preference ELO from blind head-to-head votes
LMSYS / HuggingFaceCoding Benchmarks
Human preference ELO for building a working web page from a brief
Design Arena (via OpenRouter)Human preference ELO for building things — websites, UI, games, charts, SVG
Design Arena (via OpenRouter)Math Benchmarks
Reasoning Benchmarks
Speed Benchmarks
Cost Benchmarks
Cost per 1M cached input tokens — the price that actually applies to a long agent conversation
OpenRouter APIContext Benchmarks
Available from 17 providers
The same model costs different amounts depending on who serves it. You can bring your own key for 3 of these — connect it here.
| Provider | Input / 1M | Output / 1M | Cached in | Context | Your key |
|---|---|---|---|---|---|
| Poe | $0.22 | $1.8 | $0.022 | 400K | — |
| Jiekou.AI | $0.225 | $1.8 | — | 400K | — |
| AIHubMix | $0.25 | $2 | $0.025 | 400K | — |
| Azure | $0.25 | $2 | $0.025 | 400K | Supported |
| Azure Cognitive Services | $0.25 | $2 | $0.025 | 400K | — |
| DevPass (LLM Gateway) | $0.25 | $2 | $0.025 | 400K | — |
| Eden AI | $0.25 | $2 | $0.025 | 272K | — |
| Impossibl | $0.25 | $2 | $0.025 | 400K | — |
| Kilo Gateway | $0.25 | $2 | $0.03 | 400K | — |
| LLM Gateway | $0.25 | $2 | $0.025 | 400K | — |
| NanoGPT | $0.25 | $2 | $0.025 | 400K | — |
| Ofox | $0.25 | $2 | $0.03 | 256K | — |
| OpenCode Zen | $0.25 | $2 | $0.025 | 400K | — |
| OpenRouter | $0.25 | $2 | $0.03 | 400K | Supported |
| OrcaRouter | $0.25 | $2 | $0.025 | 400K | — |
| Vercel AI Gateway | $0.25 | $2 | $0.03 | 400K | Supported |
| ZenMux | $0.25 | $2 | $0.03 | 400K | — |
GPT-5.1 Codex Mini — Benchmark Scores Overview
Scores normalized to percentage scale for visual comparison. ELO scores mapped to 0-100 range (1100-1500).
Compare GPT-5.1 Codex Mini With
GPT-5.1 Codex Mini — Frequently Asked Questions
How intelligent is GPT-5.1 Codex Mini?
GPT-5.1 Codex Mini scores 1310 on the Chatbot Arena ELO rating, making it a mid-tier AI model. This score is based on blind head-to-head human preference voting.
How much does GPT-5.1 Codex Mini cost?
GPT-5.1 Codex Mini costs $0.25 per 1M input tokens and $2.0 per 1M output tokens. This makes it one of the more affordable models.
How fast is GPT-5.1 Codex Mini?
GPT-5.1 Codex Mini generates output at 170 tokens per second, which is very fast compared to other models. The time to first token is 180 ms.
How good is GPT-5.1 Codex Mini at coding?
GPT-5.1 Codex Mini achieves 55.0% on SWE-bench Verified, demonstrating strong real-world software engineering capability. This benchmark tests the model's ability to resolve actual GitHub issues.
How good is GPT-5.1 Codex Mini at math and reasoning?
GPT-5.1 Codex Mini scores 78.0% on the MATH benchmark (competition-level mathematics). It also achieves 52.0% on GPQA Diamond, a graduate-level science reasoning benchmark.
What is the context window of GPT-5.1 Codex Mini?
GPT-5.1 Codex Mini has a context window of 400K tokens. This determines how much text, conversation history, and code the model can process in a single request.
Who created GPT-5.1 Codex Mini?
GPT-5.1 Codex Mini was created by OpenAI. It is classified as a mid model in our catalogue.
Is GPT-5.1 Codex Mini open source?
No, GPT-5.1 Codex Mini is a proprietary model. It is available through OpenAI's API and compatible providers.