Claude Sonnet 4.5 vs Kimi K2.5
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
Kimi K2.5 by Moonshot AI wins on 6 of 11 benchmarks against Claude Sonnet 4.5 by Anthropic, which leads on 5. This head-to-head comparison covers coding, math, reasoning, speed, and pricing metrics from our benchmark data.
Category-by-Category Breakdown
Coding: In coding, Claude Sonnet 4.5 scores 52.1 on AA Coding Index compared to Kimi K2.5's 46.8, while Kimi K2.5 scores 1228 on Design Arena ELO compared to Claude Sonnet 4.5's 1184, while Kimi K2.5 scores 1261 on Website Arena ELO compared to Claude Sonnet 4.5's 1202.
Reasoning: In reasoning, Kimi K2.5 scores 84.9% on GPQA Diamond compared to Claude Sonnet 4.5's 82.5%, while Claude Sonnet 4.5 scores 73.0% on τ²-Bench Airline compared to Kimi K2.5's 71.2%.
Context: In context, Claude Sonnet 4.5 scores 1.0M on Context Length compared to Kimi K2.5's 262K.
Pricing Comparison
Claude Sonnet 4.5 costs $3.0/1M input tokens and $15.0/1M output tokens, while Kimi K2.5 costs $0.45/1M input and $2.3/1M output. Kimi K2.5 is the more affordable option for API usage.
Speed Comparison
Claude Sonnet 4.5 generates output at 67 tok/s compared to Kimi K2.5's 45 tok/s, and the time to first token is 1170 ms for Claude Sonnet 4.5 versus 1210 ms for Kimi K2.5. Claude Sonnet 4.5 delivers faster throughput.
Verdict
For developers prioritizing speed, Claude Sonnet 4.5 has the edge. For those who value affordability, Kimi K2.5 is the stronger choice.
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Claude Sonnet 4.5 vs Kimi K2.5 — FAQ
Which is better, Claude Sonnet 4.5 or Kimi K2.5?
Kimi K2.5 wins on more benchmarks overall (6 vs 5). However, the best choice depends on your specific needs — each model excels in different areas.
How does Claude Sonnet 4.5 compare to Kimi K2.5 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 Kimi K2.5?
Yes, Kimi K2.5 is cheaper. Claude Sonnet 4.5 costs $3.0/1M input and $15.0/1M output tokens. Kimi K2.5 costs $0.45/1M input and $2.3/1M output tokens.
Which is faster, Claude Sonnet 4.5 or Kimi K2.5?
Claude Sonnet 4.5 is faster, generating output at 67 tok/s compared to 45 tok/s. Faster output speed means shorter wait times for API responses.
What benchmarks does the Claude Sonnet 4.5 vs Kimi K2.5 comparison cover?
This comparison covers 11 benchmarks including GPQA Diamond, Output Speed, Time to First Token, Input Cost, Output Cost, Context Length, AA Coding Index, Cached Input Cost, and more. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.