Claude Sonnet 4.5 vs DeepSeek V3.1
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
Claude Sonnet 4.5 by Anthropic wins on 11 of 15 benchmarks against DeepSeek V3.1 by DeepSeek, 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 Sonnet 4.5 scores 1380 on Chatbot Arena ELO compared to DeepSeek V3.1's 1340, while Claude Sonnet 4.5 scores 83.0% on MMLU-Pro compared to DeepSeek V3.1's 78.0%.
Coding: In coding, Claude Sonnet 4.5 scores 90.0% on HumanEval+ compared to DeepSeek V3.1's 84.0%, while Claude Sonnet 4.5 scores 77.2% on SWE-bench Verified compared to DeepSeek V3.1's 46.0%, while Claude Sonnet 4.5 scores 62.0% on LiveCodeBench compared to DeepSeek V3.1's 48.0%.
Math: In math, Claude Sonnet 4.5 scores 87.0% on MATH compared to DeepSeek V3.1's 82.0%, while Claude Sonnet 4.5 scores 95.5% on GSM8K compared to DeepSeek V3.1's 92.0%.
Reasoning: In reasoning, Claude Sonnet 4.5 scores 83.4% on GPQA Diamond compared to DeepSeek V3.1's 55.0%, while Claude Sonnet 4.5 scores 45.0% on ARC-AGI compared to DeepSeek V3.1's 35.0%.
Context: In context, Claude Sonnet 4.5 scores 1.0M on Context Length compared to DeepSeek V3.1's 164K.
Pricing Comparison
Claude Sonnet 4.5 costs $3.0/1M input tokens and $15.0/1M output tokens, while DeepSeek V3.1 costs $0.25/1M input and $0.95/1M output. DeepSeek V3.1 is the more affordable option for API usage.
Speed Comparison
Claude Sonnet 4.5 generates output at 67 tok/s compared to DeepSeek V3.1's 65 tok/s, and the time to first token is 1170 ms for Claude Sonnet 4.5 versus 450 ms for DeepSeek V3.1. Claude Sonnet 4.5 delivers faster throughput.
Verdict
For developers prioritizing coding and general intelligence and math and speed, Claude Sonnet 4.5 has the edge. For those who value affordability, DeepSeek V3.1 is the stronger choice.
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Claude Sonnet 4.5 vs DeepSeek V3.1 — FAQ
Which is better, Claude Sonnet 4.5 or DeepSeek V3.1?
Claude Sonnet 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 Sonnet 4.5 compare to DeepSeek V3.1 for coding?
Claude Sonnet 4.5 is better for coding, scoring 77.2% on SWE-bench Verified compared to 46.0%. SWE-bench tests real-world software engineering by resolving actual GitHub issues.
Is Claude Sonnet 4.5 cheaper than DeepSeek V3.1?
Yes, DeepSeek V3.1 is cheaper. Claude Sonnet 4.5 costs $3.0/1M input and $15.0/1M output tokens. DeepSeek V3.1 costs $0.25/1M input and $0.95/1M output tokens.
Which is faster, Claude Sonnet 4.5 or DeepSeek V3.1?
Claude Sonnet 4.5 is faster, generating output at 67 tok/s compared to 65 tok/s. Faster output speed means shorter wait times for API responses.
What benchmarks does the Claude Sonnet 4.5 vs DeepSeek V3.1 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.