Model Comparison
GLM-5.1 vs Grok 4.5Which is better in 2026?
Grok 4.5 significantly outperforms across most benchmarks. GLM-5.1 is 1.4x cheaper per token.
Verdict: GLM-5.1 vs Grok 4.5 — which is better?
GLM-5.1 (by Zhipu AI) and Grok 4.5 (by xAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
GLM-5.1 outperforms in 0 benchmarks, while Grok 4.5 is better at 3 benchmarks (GDPval-AA, GPQA, SWE-Bench Pro). Grok 4.5 significantly outperforms across most benchmarks.
On price, GLM-5.1 is roughly 1.4x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok 4.5 also accepts a larger context window (500,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose GLM-5.1 if…
- cost matters — it's about 1.4x cheaper per token
- you need open weights you can self-host or fine-tune
Choose Grok 4.5 if…
- you want the strongest raw capability — it leads on 3 of 3 shared benchmarks
- you process long inputs — it offers a 500,000 token context window
- you want the most recent training data — it shipped Jul 2026
Performance Benchmarks
Comparative analysis across standard metrics
GLM-5.1 outperforms in 0 benchmarks, while Grok 4.5 is better at 3 benchmarks (GDPval-AA, GPQA, SWE-Bench Pro).
Grok 4.5 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GLM-5.1 ($1.40/1M tokens) is 1.4x cheaper than Grok 4.5 ($2.00/1M tokens).
For output processing, GLM-5.1 ($4.40/1M tokens) is 1.4x cheaper than Grok 4.5 ($6.00/1M tokens).
In conclusion, Grok 4.5 is more expensive than GLM-5.1.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok 4.5 accepts 500,000 input tokens compared to GLM-5.1's 200,000 tokens. Only GLM-5.1 specifies output context (128,000 tokens).
Input Capabilities
Supported data types and modalities
Grok 4.5 supports multimodal inputs, whereas GLM-5.1 does not.
Grok 4.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.
GLM-5.1
Grok 4.5
License
Usage and distribution terms
GLM-5.1 is licensed under MIT, while Grok 4.5 uses a proprietary license.
License differences may affect how you can use these models in commercial or open-source projects.
MIT
Open weights
Proprietary
Closed source
Release Timeline
When each model was launched
GLM-5.1 was released on 2026-04-07, while Grok 4.5 was released on 2026-07-16.
Grok 4.5 is 3 months newer than GLM-5.1.
Apr 7, 2026
3 months ago
Jul 16, 2026
4 days ago
3mo newerKnowledge Cutoff
When training data ends
Grok 4.5 has a documented knowledge cutoff of 2026-02-01, while GLM-5.1's cutoff date is not specified.
We can confirm Grok 4.5's training data extends to 2026-02-01, but cannot make a direct comparison without GLM-5.1's cutoff date.
—
Feb 2026
Provider Availability
GLM-5.1 is available from FriendliAI, ZAI. Grok 4.5 is available from xAI.
GLM-5.1
Grok 4.5
Outputs Comparison
Key Takeaways
GLM-5.1
View detailsZhipu AI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GLM-5.1 and Grok 4.5 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GLM-5.1 vs Grok 4.5.