Claude Sonnet 4.5 vs GLM-5.1
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
GLM-5.1 by Zhipu AI 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, GLM-5.1 scores 26.4 on AA Intelligence Index compared to Claude Sonnet 4.5's 21.2.
Coding: In coding, GLM-5.1 scores 55.8 on AA Coding Index compared to Claude Sonnet 4.5's 52.1, while GLM-5.1 scores 1279 on Design Arena ELO compared to Claude Sonnet 4.5's 1184, while GLM-5.1 scores 1278 on Website Arena ELO compared to Claude Sonnet 4.5's 1202.
Reasoning: In reasoning, GLM-5.1 scores 82.9% on GPQA Diamond compared to Claude Sonnet 4.5's 82.5%, while GLM-5.1 scores 25.2 on AA Agentic Index compared to Claude Sonnet 4.5's 17.5, while GLM-5.1 scores 74.1% on τ²-Bench Airline compared to Claude Sonnet 4.5's 73.0%.
Context: In context, Claude Sonnet 4.5 scores 1.0M on Context Length compared to GLM-5.1's 205K.
Pricing Comparison
Claude Sonnet 4.5 costs $3.0/1M input tokens and $15.0/1M output tokens, while GLM-5.1 costs $0.97/1M input and $3.0/1M output. GLM-5.1 is the more affordable option for API usage.
Verdict
GLM-5.1 leads across the board in affordability, making it the stronger overall choice in this comparison.
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Claude Sonnet 4.5 vs GLM-5.1 — FAQ
Which is better, Claude Sonnet 4.5 or GLM-5.1?
GLM-5.1 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 GLM-5.1 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 GLM-5.1?
Yes, GLM-5.1 is cheaper. Claude Sonnet 4.5 costs $3.0/1M input and $15.0/1M output tokens. GLM-5.1 costs $0.97/1M input and $3.0/1M output tokens.
Which is faster, Claude Sonnet 4.5 or GLM-5.1?
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 GLM-5.1 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.