Claude Sonnet 4.5 vs o3 Mini
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
Claude Sonnet 4.5 by Anthropic wins on 8 of 15 benchmarks against o3 Mini by OpenAI, which leads on 6. 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, Claude Sonnet 4.5 scores 1380 on Chatbot Arena ELO compared to o3 Mini's 1320, while Claude Sonnet 4.5 scores 83.0% on MMLU-Pro compared to o3 Mini's 78.0%.
Coding: In coding, Claude Sonnet 4.5 scores 90.0% on HumanEval+ compared to o3 Mini's 87.0%, while Claude Sonnet 4.5 scores 77.2% on SWE-bench Verified compared to o3 Mini's 50.0%, while Claude Sonnet 4.5 scores 62.0% on LiveCodeBench compared to o3 Mini's 55.0%.
Math: In math, o3 Mini scores 93.0% on MATH compared to Claude Sonnet 4.5's 87.0%, while o3 Mini scores 97.0% on GSM8K compared to Claude Sonnet 4.5's 95.5%.
Reasoning: In reasoning, Claude Sonnet 4.5 scores 83.4% on GPQA Diamond compared to o3 Mini's 77.0%, while both score 45.0% on ARC-AGI.
Context: In context, Claude Sonnet 4.5 scores 1.0M on Context Length compared to o3 Mini's 200K.
Pricing Comparison
Claude Sonnet 4.5 costs $3.0/1M input tokens and $15.0/1M output tokens, while o3 Mini costs $1.1/1M input and $4.4/1M output. o3 Mini is the more affordable option for API usage.
Speed Comparison
Claude Sonnet 4.5 generates output at 67 tok/s compared to o3 Mini's 100 tok/s, and the time to first token is 1170 ms for Claude Sonnet 4.5 versus 400 ms for o3 Mini. o3 Mini delivers faster throughput.
Verdict
For developers prioritizing coding and general intelligence, Claude Sonnet 4.5 has the edge. For those who value math and affordability and speed, o3 Mini is the stronger choice.
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Claude Sonnet 4.5 vs o3 Mini — FAQ
Which is better, Claude Sonnet 4.5 or o3 Mini?
Claude Sonnet 4.5 wins on more benchmarks overall (8 vs 6). However, the best choice depends on your specific needs — each model excels in different areas.
How does Claude Sonnet 4.5 compare to o3 Mini for coding?
Claude Sonnet 4.5 is better for coding, scoring 77.2% on SWE-bench Verified compared to 50.0%. SWE-bench tests real-world software engineering by resolving actual GitHub issues.
Is Claude Sonnet 4.5 cheaper than o3 Mini?
Yes, o3 Mini is cheaper. Claude Sonnet 4.5 costs $3.0/1M input and $15.0/1M output tokens. o3 Mini costs $1.1/1M input and $4.4/1M output tokens.
Which is faster, Claude Sonnet 4.5 or o3 Mini?
o3 Mini is faster, generating output at 100 tok/s compared to 67 tok/s. Faster output speed means shorter wait times for API responses.
What benchmarks does the Claude Sonnet 4.5 vs o3 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.