Claude 3.5 Sonnet vs Claude Opus 4.5
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
Claude Opus 4.5 by Anthropic wins on 11 of 16 benchmarks against Claude 3.5 Sonnet by Anthropic, which leads on 4. 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 Opus 4.5 scores 1468 on Chatbot Arena ELO compared to Claude 3.5 Sonnet's 1268, while Claude Opus 4.5 scores 89.5% on MMLU-Pro compared to Claude 3.5 Sonnet's 73.0%, while Claude Opus 4.5 scores 90.0% on IFEval compared to Claude 3.5 Sonnet's 86.0%.
Coding: In coding, Claude Opus 4.5 scores 92.0% on HumanEval+ compared to Claude 3.5 Sonnet's 81.7%, while Claude Opus 4.5 scores 80.9% on SWE-bench Verified compared to Claude 3.5 Sonnet's 49.0%, while Claude Opus 4.5 scores 70.0% on LiveCodeBench compared to Claude 3.5 Sonnet's 38.0%.
Math: In math, Claude Opus 4.5 scores 90.0% on MATH compared to Claude 3.5 Sonnet's 78.3%, while Claude Opus 4.5 scores 96.5% on GSM8K compared to Claude 3.5 Sonnet's 91.0%, while Claude Opus 4.5 scores 72.0% on AIME 2025 compared to Claude 3.5 Sonnet's 23.0%.
Reasoning: In reasoning, Claude Opus 4.5 scores 87.0% on GPQA Diamond compared to Claude 3.5 Sonnet's 59.4%, while Claude Opus 4.5 scores 57.0% on ARC-AGI compared to Claude 3.5 Sonnet's 15.0%.
Context: In context, both score 200K on Context Length.
Pricing Comparison
Claude 3.5 Sonnet costs $3.0/1M input tokens and $15.0/1M output tokens, while Claude Opus 4.5 costs $5.0/1M input and $25.0/1M output. Claude 3.5 Sonnet is the more affordable option for API usage.
Speed Comparison
Claude 3.5 Sonnet generates output at 70 tok/s compared to Claude Opus 4.5's 50 tok/s, and the time to first token is 400 ms for Claude 3.5 Sonnet versus 1700 ms for Claude Opus 4.5. Claude 3.5 Sonnet delivers faster throughput.
Verdict
For developers prioritizing affordability and speed, Claude 3.5 Sonnet has the edge. For those who value coding and general intelligence and math, Claude Opus 4.5 is the stronger choice.
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Claude 3.5 Sonnet vs Claude Opus 4.5 — FAQ
Which is better, Claude 3.5 Sonnet or Claude Opus 4.5?
Claude Opus 4.5 wins on more benchmarks overall (11 vs 4). However, the best choice depends on your specific needs — each model excels in different areas.
How does Claude 3.5 Sonnet compare to Claude Opus 4.5 for coding?
Claude Opus 4.5 is better for coding, scoring 80.9% on SWE-bench Verified compared to 49.0%. SWE-bench tests real-world software engineering by resolving actual GitHub issues.
Is Claude 3.5 Sonnet cheaper than Claude Opus 4.5?
Yes, Claude 3.5 Sonnet is cheaper. Claude 3.5 Sonnet costs $3.0/1M input and $15.0/1M output tokens. Claude Opus 4.5 costs $5.0/1M input and $25.0/1M output tokens.
Which is faster, Claude 3.5 Sonnet or Claude Opus 4.5?
Claude 3.5 Sonnet is faster, generating output at 70 tok/s compared to 50 tok/s. Faster output speed means shorter wait times for API responses.
What benchmarks does the Claude 3.5 Sonnet vs Claude Opus 4.5 comparison cover?
This comparison covers 16 benchmarks including Chatbot Arena ELO, MMLU-Pro, HumanEval+, IFEval, MATH, GPQA Diamond, SWE-bench Verified, Output Speed, and more. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.