GLM-5.3 vs Grok 4 Fast
GLM-5.3 significantly outperforms across most benchmarks. Grok 4 Fast is 7.8x cheaper per token.
Zhipu AI · xAI · Updated for 2026
Which is better?
GLM-5.3 outperforms in 1 benchmarks (Humanity's Last Exam), while Grok 4 Fast is better at 0 benchmarks. GLM-5.3 significantly outperforms across most benchmarks.
On price, Grok 4 Fast is roughly 7.8x 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.
Based on current benchmark, pricing, and model metadata for 2026.
Choose GLM-5.3
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- you want the most recent training data — it shipped Aug 2026
Choose Grok 4 Fast
- cost matters — it's about 7.8x cheaper per token
- you process long inputs — it offers a 2,000,000 token context window
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
GLM-5.3 outperforms in 1 benchmarks (Humanity's Last Exam), while Grok 4 Fast is better at 0 benchmarks.
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-5.3 ($1.40/1M tokens) is 7.0x more expensive than Grok 4 Fast ($0.20/1M tokens).
For output processing, GLM-5.3 ($4.40/1M tokens) is 8.8x more expensive than Grok 4 Fast ($0.50/1M tokens).
In conclusion, GLM-5.3 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-5.3's 1,000,000 tokens. GLM-5.3 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-5.3 does not.
Grok 4 Fast can handle both text and other forms of data like images, making it suitable for multimodal applications.
GLM-5.3
Grok 4 Fast
Release Timeline
When each model was launched
GLM-5.3 was released on 2026-08-14, while Grok 4 Fast was released on 2025-08-28.
GLM-5.3 is 12 months newer than Grok 4 Fast.
Aug 14, 2026
1 weeks ago
11mo newerAug 28, 2025
12 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-5.3 is available from ZAI. Grok 4 Fast is available from xAI.
GLM-5.3
Grok 4 Fast
Outputs Comparison
Judge for yourself.
Run your own prompts against GLM-5.3 and Grok 4 Fast side-by-side, then vote on the output you prefer.
FAQ
Common questions about GLM-5.3 vs Grok 4 Fast.