GLM-4.5-Air vs GPT-5.1
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
GPT-5.1 by OpenAI wins on 5 of 8 benchmarks against GLM-4.5-Air by Zhipu AI, which leads on 3. This head-to-head comparison covers coding, math, reasoning, speed, and pricing metrics from our benchmark data.
Category-by-Category Breakdown
Coding: In coding, GPT-5.1 scores 1158 on Design Arena ELO compared to GLM-4.5-Air's 1145, while GPT-5.1 scores 1179 on Website Arena ELO compared to GLM-4.5-Air's 1159.
Reasoning: In reasoning, GPT-5.1 scores 86.2% on GPQA Diamond compared to GLM-4.5-Air's 64.7%, while GPT-5.1 scores 75.7% on τ²-Bench Airline compared to GLM-4.5-Air's 70.9%.
Context: In context, GPT-5.1 scores 400K on Context Length compared to GLM-4.5-Air's 131K.
Pricing Comparison
GLM-4.5-Air costs $0.13/1M input tokens and $0.85/1M output tokens, while GPT-5.1 costs $1.3/1M input and $10.0/1M output. GLM-4.5-Air is the more affordable option for API usage.
Verdict
GLM-4.5-Air leads across the board in affordability, making it the stronger overall choice in this comparison.
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GLM-4.5-Air vs GPT-5.1 — FAQ
Which is better, GLM-4.5-Air or GPT-5.1?
GPT-5.1 wins on more benchmarks overall (5 vs 3). However, the best choice depends on your specific needs — each model excels in different areas.
How does GLM-4.5-Air compare to GPT-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 GLM-4.5-Air cheaper than GPT-5.1?
Yes, GLM-4.5-Air is cheaper. GLM-4.5-Air costs $0.13/1M input and $0.85/1M output tokens. GPT-5.1 costs $1.3/1M input and $10.0/1M output tokens.
Which is faster, GLM-4.5-Air or GPT-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 GLM-4.5-Air vs GPT-5.1 comparison cover?
This comparison covers 8 benchmarks including GPQA Diamond, Input Cost, Output Cost, Context Length, Cached Input Cost, Design Arena ELO, τ²-Bench Airline, Website Arena ELO. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.