GLM-5.3-Flash vs GPT-5.1

Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.

GLM-5.3-Flash by Zhipu AI wins on 7 of 9 benchmarks against GPT-5.1 by OpenAI, which leads on 2. This head-to-head comparison covers coding, math, reasoning, speed, and pricing metrics from our benchmark data.

Category-by-Category Breakdown

Coding: In coding, GLM-5.3-Flash scores 71.5 on AA Coding Index compared to GPT-5.1's 49.4, while GLM-5.3-Flash scores 1310 on Design Arena ELO compared to GPT-5.1's 1158, while GLM-5.3-Flash scores 1286 on Website Arena ELO compared to GPT-5.1's 1179.

Reasoning: In reasoning, GPT-5.1 scores 86.2% on GPQA Diamond compared to GLM-5.3-Flash's 85.8%, while GPT-5.1 scores 75.7% on τ²-Bench Airline compared to GLM-5.3-Flash's 75.3%.

Context: In context, GLM-5.3-Flash scores 1.3M on Context Length compared to GPT-5.1's 400K.

Pricing Comparison

GLM-5.3-Flash costs $0.15/1M input tokens and $0.50/1M output tokens, while GPT-5.1 costs $1.3/1M input and $10.0/1M output. GLM-5.3-Flash is the more affordable option for API usage.

Verdict

GLM-5.3-Flash leads across the board in affordability, making it the stronger overall choice in this comparison.

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GLM-5.3-Flash vs GPT-5.1 — FAQ

Which is better, GLM-5.3-Flash or GPT-5.1?

GLM-5.3-Flash wins on more benchmarks overall (7 vs 2). However, the best choice depends on your specific needs — each model excels in different areas.

How does GLM-5.3-Flash 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-5.3-Flash cheaper than GPT-5.1?

Yes, GLM-5.3-Flash is cheaper. GLM-5.3-Flash costs $0.15/1M input and $0.50/1M output tokens. GPT-5.1 costs $1.3/1M input and $10.0/1M output tokens.

Which is faster, GLM-5.3-Flash 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-5.3-Flash vs GPT-5.1 comparison cover?

This comparison covers 9 benchmarks including GPQA Diamond, Input Cost, Output Cost, Context Length, AA Coding Index, Cached Input Cost, Design Arena ELO, τ²-Bench Airline, and more. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.