GPT-5.1 Codex vs o1 Mini
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
GPT-5.1 Codex by OpenAI wins on 12 of 14 benchmarks against o1 Mini by OpenAI, which leads on 2. This head-to-head comparison covers coding, math, reasoning, speed, and pricing metrics from our benchmark data.
Category-by-Category Breakdown
General Intelligence: In general intelligence, GPT-5.1 Codex scores 1395 on Chatbot Arena ELO compared to o1 Mini's 1300, while GPT-5.1 Codex scores 82.0% on MMLU-Pro compared to o1 Mini's 75.0%.
Coding: In coding, GPT-5.1 Codex scores 96.0% on HumanEval+ compared to o1 Mini's 89.0%, while GPT-5.1 Codex scores 78.0% on SWE-bench Verified compared to o1 Mini's 45.0%, while GPT-5.1 Codex scores 85.0% on LiveCodeBench compared to o1 Mini's 48.0%.
Math: In math, o1 Mini scores 90.0% on MATH compared to GPT-5.1 Codex's 85.0%, while o1 Mini scores 96.0% on GSM8K compared to GPT-5.1 Codex's 95.0%.
Reasoning: In reasoning, GPT-5.1 Codex scores 65.0% on GPQA Diamond compared to o1 Mini's 60.0%, while GPT-5.1 Codex scores 52.0% on ARC-AGI compared to o1 Mini's 25.0%.
Context: In context, GPT-5.1 Codex scores 400K on Context Length compared to o1 Mini's 128K.
Pricing Comparison
GPT-5.1 Codex costs $1.3/1M input tokens and $10.0/1M output tokens, while o1 Mini costs $3.0/1M input and $12.0/1M output. GPT-5.1 Codex is the more affordable option for API usage.
Speed Comparison
GPT-5.1 Codex generates output at 85 tok/s compared to o1 Mini's 80 tok/s, and the time to first token is 400 ms for GPT-5.1 Codex versus 500 ms for o1 Mini. GPT-5.1 Codex delivers faster throughput.
Verdict
For developers prioritizing coding and general intelligence and affordability and speed, GPT-5.1 Codex has the edge. For those who value math, o1 Mini is the stronger choice.
View Individual Model Pages
GPT-5.1 Codex vs o1 Mini — FAQ
Which is better, GPT-5.1 Codex or o1 Mini?
GPT-5.1 Codex wins on more benchmarks overall (12 vs 2). However, the best choice depends on your specific needs — each model excels in different areas.
How does GPT-5.1 Codex compare to o1 Mini for coding?
GPT-5.1 Codex is better for coding, scoring 78.0% on SWE-bench Verified compared to 45.0%. SWE-bench tests real-world software engineering by resolving actual GitHub issues.
Is GPT-5.1 Codex cheaper than o1 Mini?
Yes, GPT-5.1 Codex is cheaper. GPT-5.1 Codex costs $1.3/1M input and $10.0/1M output tokens. o1 Mini costs $3.0/1M input and $12.0/1M output tokens.
Which is faster, GPT-5.1 Codex or o1 Mini?
GPT-5.1 Codex is faster, generating output at 85 tok/s compared to 80 tok/s. Faster output speed means shorter wait times for API responses.
What benchmarks does the GPT-5.1 Codex vs o1 Mini comparison cover?
This comparison covers 14 benchmarks including Chatbot Arena ELO, MMLU-Pro, HumanEval+, MATH, GPQA Diamond, SWE-bench Verified, Output Speed, LiveCodeBench, and more. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.