Model Comparison
GLM-5 vs Grok 4 FastWhich is better in 2026?
GLM-5 significantly outperforms across most benchmarks. Grok 4 Fast is 5.6x cheaper per token.
Verdict: GLM-5 vs Grok 4 Fast — which is better?
GLM-5 (by Zhipu AI) and Grok 4 Fast (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 outperforms in 1 benchmarks (BrowseComp), while Grok 4 Fast is better at 0 benchmarks. GLM-5 significantly outperforms across most benchmarks.
On price, Grok 4 Fast is roughly 5.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok 4 Fast also accepts a larger context window (2,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose GLM-5 if…
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- you want the most recent training data — it shipped Feb 2026
- you need open weights you can self-host or fine-tune
Choose Grok 4 Fast if…
- cost matters — it's about 5.6x cheaper per token
- you process long inputs — it offers a 2,000,000 token context window
Performance Benchmarks
Comparative analysis across standard metrics
GLM-5 outperforms in 1 benchmarks (BrowseComp), while Grok 4 Fast is better at 0 benchmarks.
GLM-5 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GLM-5 ($1.00/1M tokens) is 5.0x more expensive than Grok 4 Fast ($0.20/1M tokens).
For output processing, GLM-5 ($3.20/1M tokens) is 6.4x more expensive than Grok 4 Fast ($0.50/1M tokens).
In conclusion, GLM-5 is more expensive than Grok 4 Fast.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok 4 Fast accepts 2,000,000 input tokens compared to GLM-5's 200,000 tokens. GLM-5 can generate longer responses up to 128,000 tokens, while Grok 4 Fast is limited to 30,000 tokens.
Input Capabilities
Supported data types and modalities
Grok 4 Fast supports multimodal inputs, whereas GLM-5 does not.
Grok 4 Fast can handle both text and other forms of data like images, making it suitable for multimodal applications.
GLM-5
Grok 4 Fast
License
Usage and distribution terms
GLM-5 is licensed under MIT, while Grok 4 Fast 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 was released on 2026-02-11, while Grok 4 Fast was released on 2025-08-28.
GLM-5 is 6 months newer than Grok 4 Fast.
Feb 11, 2026
3 months ago
5mo newerAug 28, 2025
9 months ago
Knowledge 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 is available from FriendliAI, ZAI. Grok 4 Fast is available from xAI.
GLM-5
Grok 4 Fast
Outputs Comparison
Key Takeaways
GLM-5
View detailsZhipu AI
Detailed Comparison
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FAQ
Common questions about GLM-5 vs Grok 4 Fast.