GLM-5.3-Flash vs Grok 4 Fast
GLM-5.3-Flash leads the LLM Stats Score 50.7 to 32.0. GLM-5.3-Flash is 1.2x cheaper per token.
Zhipu AI · xAI · Updated for 2026
Which is better?
GLM-5.3-Flash leads the overall LLM Stats Score 50.7 to 32.0, ranking #16 overall.
In the 1 individual benchmarks reported for both models, GLM-5.3-Flash wins 1; this is a narrower head-to-head signal than the composite indexes.
On price, GLM-5.3-Flash is roughly 1.2x 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 LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose GLM-5.3-Flash
- overall performance matters — it scores 50.7 and ranks #16 on LLM Stats
- your work emphasizes reasoning and agents — it leads those capability indexes
- you value its reported benchmark strengths — it wins 1 of 1 exact shared results
- cost matters — it's about 1.2x cheaper per token
- you want the most recent training data — it shipped Aug 2026
- you need open weights you can self-host or fine-tune
Choose Grok 4 Fast
- you process long inputs — it offers a 2,000,000 token context window
At a glance
The differences that matter most.
Individual benchmarks
15 reported for GLM-5.3-Flash · 7 for Grok 4 Fast
GLM-5.3-Flash outperforms in 1 benchmarks (Humanity's Last Exam), while Grok 4 Fast is better at 0 benchmarks.
GLM-5.3-Flash significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GLM-5.3-Flash ($0.15/1M tokens) is 1.3x cheaper than Grok 4 Fast ($0.20/1M tokens).
For output processing, GLM-5.3-Flash ($0.50/1M tokens) costs the same as Grok 4 Fast ($0.50/1M tokens).
In conclusion, Grok 4 Fast is more expensive than GLM-5.3-Flash.*
* 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-Flash's 1,048,576 tokens. GLM-5.3-Flash can generate longer responses up to 131,072 tokens, while Grok 4 Fast is limited to 30,000 tokens.
Input capabilities
Documented input modalities across available providers
Both GLM-5.3-Flash and Grok 4 Fast support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GLM-5.3-Flash
Grok 4 Fast
License
Usage and distribution terms
GLM-5.3-Flash 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-5.3-Flash was released on 2026-08-26, while Grok 4 Fast was released on 2025-08-28.
GLM-5.3-Flash is 12 months newer than Grok 4 Fast.
Aug 26, 2026
1 weeks ago
12mo newerAug 28, 2025
1.0 years 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-Flash is available from DeepInfra, FriendliAI, Novita, ZAI. Grok 4 Fast is available from xAI.
GLM-5.3-Flash
Grok 4 Fast
Outputs Comparison
Judge for yourself.
Run your own prompts against GLM-5.3-Flash and Grok 4 Fast side-by-side, then vote on the output you prefer.
FAQ
Common questions about GLM-5.3-Flash vs Grok 4 Fast.