Claude 3 Opus vs GPT-5.1 Codex Mini
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
GPT-5.1 Codex Mini by OpenAI wins on 13 of 14 benchmarks against Claude 3 Opus by Anthropic, which leads on 1. 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 Mini scores 1310 on Chatbot Arena ELO compared to Claude 3 Opus's 1240, while GPT-5.1 Codex Mini scores 72.0% on MMLU-Pro compared to Claude 3 Opus's 68.0%.
Coding: In coding, GPT-5.1 Codex Mini scores 88.0% on HumanEval+ compared to Claude 3 Opus's 78.0%, while GPT-5.1 Codex Mini scores 55.0% on SWE-bench Verified compared to Claude 3 Opus's 22.0%, while GPT-5.1 Codex Mini scores 65.0% on LiveCodeBench compared to Claude 3 Opus's 32.0%.
Math: In math, GPT-5.1 Codex Mini scores 78.0% on MATH compared to Claude 3 Opus's 68.0%, while GPT-5.1 Codex Mini scores 92.0% on GSM8K compared to Claude 3 Opus's 88.0%.
Reasoning: In reasoning, Claude 3 Opus scores 59.4% on GPQA Diamond compared to GPT-5.1 Codex Mini's 52.0%, while GPT-5.1 Codex Mini scores 35.0% on ARC-AGI compared to Claude 3 Opus's 8.0%.
Context: In context, GPT-5.1 Codex Mini scores 400K on Context Length compared to Claude 3 Opus's 200K.
Pricing Comparison
Claude 3 Opus costs $15.0/1M input tokens and $75.0/1M 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
Claude 3 Opus generates output at 25 tok/s compared to GPT-5.1 Codex Mini's 170 tok/s, and the time to first token is 800 ms for Claude 3 Opus versus 180 ms for GPT-5.1 Codex Mini. GPT-5.1 Codex Mini delivers faster throughput.
Verdict
GPT-5.1 Codex Mini leads across the board in coding, general intelligence, math, affordability, speed, making it the stronger overall choice in this comparison.
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Claude 3 Opus vs GPT-5.1 Codex Mini — FAQ
Which is better, Claude 3 Opus or GPT-5.1 Codex Mini?
GPT-5.1 Codex Mini wins on more benchmarks overall (13 vs 1). However, the best choice depends on your specific needs — each model excels in different areas.
How does Claude 3 Opus compare to GPT-5.1 Codex Mini for coding?
GPT-5.1 Codex Mini is better for coding, scoring 55.0% on SWE-bench Verified compared to 22.0%. SWE-bench tests real-world software engineering by resolving actual GitHub issues.
Is Claude 3 Opus cheaper than GPT-5.1 Codex Mini?
Yes, GPT-5.1 Codex Mini is cheaper. Claude 3 Opus costs $15.0/1M input and $75.0/1M output tokens. GPT-5.1 Codex Mini costs $0.25/1M input and $2.0/1M output tokens.
Which is faster, Claude 3 Opus or GPT-5.1 Codex Mini?
GPT-5.1 Codex Mini is faster, generating output at 170 tok/s compared to 25 tok/s. Faster output speed means shorter wait times for API responses.
What benchmarks does the Claude 3 Opus vs GPT-5.1 Codex 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.