Claude Sonnet 4.5 vs DeepSeek V4 Flash 0731
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
DeepSeek V4 Flash 0731 by Alibaba wins on 10 of 11 benchmarks against Claude Sonnet 4.5 by Anthropic, which leads on 1. 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, DeepSeek V4 Flash 0731 scores 34.5 on AA Intelligence Index compared to Claude Sonnet 4.5's 21.2.
Coding: In coding, DeepSeek V4 Flash 0731 scores 69.1 on AA Coding Index compared to Claude Sonnet 4.5's 52.1, while DeepSeek V4 Flash 0731 scores 1217 on Design Arena ELO compared to Claude Sonnet 4.5's 1184, while DeepSeek V4 Flash 0731 scores 1250 on Website Arena ELO compared to Claude Sonnet 4.5's 1202.
Reasoning: In reasoning, DeepSeek V4 Flash 0731 scores 85.1% on GPQA Diamond compared to Claude Sonnet 4.5's 82.5%, while DeepSeek V4 Flash 0731 scores 41.7 on AA Agentic Index compared to Claude Sonnet 4.5's 17.5, while Claude Sonnet 4.5 scores 73.0% on τ²-Bench Airline compared to DeepSeek V4 Flash 0731's 72.8%.
Context: In context, DeepSeek V4 Flash 0731 scores 1.3M on Context Length compared to Claude Sonnet 4.5's 1.0M.
Pricing Comparison
Claude Sonnet 4.5 costs $3.0/1M input tokens and $15.0/1M output tokens, while DeepSeek V4 Flash 0731 costs $0.06/1M input and $0.12/1M output. DeepSeek V4 Flash 0731 is the more affordable option for API usage.
Verdict
DeepSeek V4 Flash 0731 leads across the board in affordability, making it the stronger overall choice in this comparison.
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Claude Sonnet 4.5 vs DeepSeek V4 Flash 0731 — FAQ
Which is better, Claude Sonnet 4.5 or DeepSeek V4 Flash 0731?
DeepSeek V4 Flash 0731 wins on more benchmarks overall (10 vs 1). However, the best choice depends on your specific needs — each model excels in different areas.
How does Claude Sonnet 4.5 compare to DeepSeek V4 Flash 0731 for coding?
SWE-bench Verified data is not available for both models. Check the detailed comparison charts above for other coding-related metrics.
Is Claude Sonnet 4.5 cheaper than DeepSeek V4 Flash 0731?
Yes, DeepSeek V4 Flash 0731 is cheaper. Claude Sonnet 4.5 costs $3.0/1M input and $15.0/1M output tokens. DeepSeek V4 Flash 0731 costs $0.06/1M input and $0.12/1M output tokens.
Which is faster, Claude Sonnet 4.5 or DeepSeek V4 Flash 0731?
Output speed data is not available for both models. Check the speed section of the comparison above for available performance data.
What benchmarks does the Claude Sonnet 4.5 vs DeepSeek V4 Flash 0731 comparison cover?
This comparison covers 11 benchmarks including GPQA Diamond, Input Cost, Output Cost, Context Length, AA Intelligence Index, AA Coding Index, AA Agentic Index, Cached Input Cost, and more. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.