Claude Sonnet 5.5 vs DeepSeek-R1

A direct, empirical evaluation of Claude Sonnet 5.5 (Anthropic) against DeepSeek-R1 (DeepSeek-AI).

Claude Sonnet 5.5

Developed by Anthropic · Proprietary Frontier Dynamic Hybrid Reasoner parameters

Terminal-Bench 4.0 execution (70.6%), SWE-bench Verified coding (82.4%), GitHub Copilot multi-file edits, and low-latency autonomous agentic coding at $2/$10 pricing.

DeepSeek-R1

Developed by DeepSeek-AI · 671B parameters

Olympiad mathematics, logic verification, and autonomous thinking chains.

Metric Claude Sonnet 5.5 DeepSeek-R1
SWE-bench Verified 82.4% 49.2%
MMLU-Pro 88.4% 84%
MATH-500 95.2% 97.3%
Context Window 1,000,000 tokens 128,000 tokens
Input Pricing (per 1M) $2.00 $0.55
Output Pricing (per 1M) $10.00 $2.19