GLM-5.1 vs GLM-5.3
GLM-5.3 significantly outperforms across most benchmarks. GLM-5.1 and GLM-5.3 cost the same.
Zhipu AI · Zhipu AI · Updated for 2026
Which is better?
GLM-5.1 outperforms in 0 benchmarks, while GLM-5.3 is better at 5 benchmarks (CyberGym, FrontierSWE, Humanity's Last Exam, NL2Repo, Toolathlon). GLM-5.3 significantly outperforms across most benchmarks.
GLM-5.3 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current benchmark, pricing, and model metadata for 2026.
Choose GLM-5.1
- you need open weights you can self-host or fine-tune
Choose GLM-5.3
- you want the strongest raw capability — it leads on 5 of 5 shared benchmarks
- you process long inputs — it offers a 1,000,000 token context window
- you want the most recent training data — it shipped Aug 2026
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
GLM-5.1 outperforms in 0 benchmarks, while GLM-5.3 is better at 5 benchmarks (CyberGym, FrontierSWE, Humanity's Last Exam, NL2Repo, Toolathlon).
GLM-5.3 significantly outperforms across most benchmarks.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GLM-5.1 ($1.40/1M tokens) costs the same as GLM-5.3 ($1.40/1M tokens).
For output processing, GLM-5.1 ($4.40/1M tokens) costs the same as GLM-5.3 ($4.40/1M tokens).
In conclusion, GLM-5.1 and GLM-5.3 cost the same.*
* Using a 3:1 ratio of input to output tokens
Model Size
Parameter count comparison
GLM-5.1 has 1.0B more parameters than GLM-5.3, making it 0.1% larger.
Context Window
Maximum input and output token capacity
GLM-5.3 accepts 1,000,000 input tokens compared to GLM-5.1's 200,000 tokens. Both models can generate responses up to 128,000 tokens.
Release Timeline
When each model was launched
GLM-5.1 was released on 2026-04-07, while GLM-5.3 was released on 2026-08-14.
GLM-5.3 is 4 months newer than GLM-5.1.
Apr 7, 2026
4 months ago
Aug 14, 2026
1 weeks ago
4mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
GLM-5.1 is available from FriendliAI, ZAI. GLM-5.3 is available from ZAI.
GLM-5.1
GLM-5.3
Outputs Comparison
Judge for yourself.
Run your own prompts against GLM-5.1 and GLM-5.3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GLM-5.1 vs GLM-5.3.