Claude Sonnet 4.5 vs o3 Pro
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
o3 Pro by OpenAI wins on 8 of 14 benchmarks against Claude Sonnet 4.5 by Anthropic, 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, o3 Pro scores 1410 on Chatbot Arena ELO compared to Claude Sonnet 4.5's 1380, while o3 Pro scores 86.0% on MMLU-Pro compared to Claude Sonnet 4.5's 83.0%.
Coding: In coding, o3 Pro scores 92.0% on HumanEval+ compared to Claude Sonnet 4.5's 90.0%, while Claude Sonnet 4.5 scores 77.2% on SWE-bench Verified compared to o3 Pro's 70.0%, while o3 Pro scores 75.0% on LiveCodeBench compared to Claude Sonnet 4.5's 62.0%.
Math: In math, o3 Pro scores 97.0% on MATH compared to Claude Sonnet 4.5's 87.0%, while o3 Pro scores 99.0% on GSM8K compared to Claude Sonnet 4.5's 95.5%.
Reasoning: In reasoning, o3 Pro scores 85.0% on GPQA Diamond compared to Claude Sonnet 4.5's 83.4%, while o3 Pro scores 70.0% on ARC-AGI compared to Claude Sonnet 4.5's 45.0%.
Context: In context, Claude Sonnet 4.5 scores 1.0M on Context Length compared to o3 Pro's 200K.
Pricing Comparison
Claude Sonnet 4.5 costs $3.0/1M input tokens and $15.0/1M output tokens, while o3 Pro costs $20.0/1M input and $80.0/1M output. Claude Sonnet 4.5 is the more affordable option for API usage.
Speed Comparison
Claude Sonnet 4.5 generates output at 67 tok/s compared to o3 Pro's 25 tok/s, and the time to first token is 1170 ms for Claude Sonnet 4.5 versus 1200 ms for o3 Pro. Claude Sonnet 4.5 delivers faster throughput.
Verdict
For developers prioritizing coding and affordability and speed, Claude Sonnet 4.5 has the edge. For those who value general intelligence and math, o3 Pro is the stronger choice.
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Claude Sonnet 4.5 vs o3 Pro — FAQ
Which is better, Claude Sonnet 4.5 or o3 Pro?
o3 Pro 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 Pro for coding?
Claude Sonnet 4.5 is better for coding, scoring 77.2% on SWE-bench Verified compared to 70.0%. SWE-bench tests real-world software engineering by resolving actual GitHub issues.
Is Claude Sonnet 4.5 cheaper than o3 Pro?
Yes, Claude Sonnet 4.5 is cheaper. Claude Sonnet 4.5 costs $3.0/1M input and $15.0/1M output tokens. o3 Pro costs $20.0/1M input and $80.0/1M output tokens.
Which is faster, Claude Sonnet 4.5 or o3 Pro?
Claude Sonnet 4.5 is faster, generating output at 67 tok/s compared to 25 tok/s. Faster output speed means shorter wait times for API responses.
What benchmarks does the Claude Sonnet 4.5 vs o3 Pro 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.