GPT-5 vs GPT-5.1 Codex Mini
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
GPT-5 by OpenAI wins on 9 of 15 benchmarks against GPT-5.1 Codex Mini by OpenAI, which leads on 5. 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 scores 1390 on Chatbot Arena ELO compared to GPT-5.1 Codex Mini's 1310, while GPT-5 scores 86.0% on MMLU-Pro compared to GPT-5.1 Codex Mini's 72.0%.
Coding: In coding, GPT-5 scores 92.0% on HumanEval+ compared to GPT-5.1 Codex Mini's 88.0%, while GPT-5 scores 74.9% on SWE-bench Verified compared to GPT-5.1 Codex Mini's 55.0%, while GPT-5 scores 78.0% on LiveCodeBench compared to GPT-5.1 Codex Mini's 65.0%.
Math: In math, GPT-5 scores 94.6% on MATH compared to GPT-5.1 Codex Mini's 78.0%, while GPT-5 scores 98.0% on GSM8K compared to GPT-5.1 Codex Mini's 92.0%.
Reasoning: In reasoning, GPT-5 scores 87.3% on GPQA Diamond compared to GPT-5.1 Codex Mini's 52.0%, while GPT-5 scores 50.0% on ARC-AGI compared to GPT-5.1 Codex Mini's 35.0%.
Context: In context, both score 400K on Context Length.
Pricing Comparison
GPT-5 costs $1.3/1M input tokens and $10.0/1M output tokens, while GPT-5.1 Codex Mini costs $0.25/1M input and $2.0/1M output. GPT-5.1 Codex Mini is the more affordable option for API usage.
Speed Comparison
GPT-5 generates output at 100 tok/s compared to GPT-5.1 Codex Mini's 170 tok/s, and the time to first token is 320 ms for GPT-5 versus 180 ms for GPT-5.1 Codex Mini. GPT-5.1 Codex Mini delivers faster throughput.
Verdict
For developers prioritizing coding and general intelligence and math, GPT-5 has the edge. For those who value affordability and speed, GPT-5.1 Codex Mini is the stronger choice.
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GPT-5 vs GPT-5.1 Codex Mini — FAQ
Which is better, GPT-5 or GPT-5.1 Codex Mini?
GPT-5 wins on more benchmarks overall (9 vs 5). However, the best choice depends on your specific needs — each model excels in different areas.
How does GPT-5 compare to GPT-5.1 Codex Mini for coding?
GPT-5 is better for coding, scoring 74.9% on SWE-bench Verified compared to 55.0%. SWE-bench tests real-world software engineering by resolving actual GitHub issues.
Is GPT-5 cheaper than GPT-5.1 Codex Mini?
Yes, GPT-5.1 Codex Mini is cheaper. GPT-5 costs $1.3/1M input and $10.0/1M output tokens. GPT-5.1 Codex Mini costs $0.25/1M input and $2.0/1M output tokens.
Which is faster, GPT-5 or GPT-5.1 Codex Mini?
GPT-5.1 Codex Mini is faster, generating output at 170 tok/s compared to 100 tok/s. Faster output speed means shorter wait times for API responses.
What benchmarks does the GPT-5 vs GPT-5.1 Codex Mini comparison cover?
This comparison covers 15 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.