Grok 4 Fast vs Hy4 preview
Hy4 preview leads the LLM Stats Score 51.1 to 32.0.
xAI · Tencent · Updated for 2026
Which is better?
Hy4 preview leads the overall LLM Stats Score 51.1 to 32.0, ranking #14 overall.
In the 1 individual benchmarks reported for both models, Hy4 preview wins 1; this is a narrower head-to-head signal than the composite indexes.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Grok 4 Fast
- you want predictable pricing at $0.20/M input and $0.50/M output
Choose Hy4 preview
- overall performance matters — it scores 51.1 and ranks #14 on LLM Stats
- your work emphasizes reasoning and coding — it leads those capability indexes
- you value its reported benchmark strengths — it wins 1 of 1 exact shared results
- you want the most recent training data — it shipped Aug 2026
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
7 reported for Grok 4 Fast · 32 for Hy4 preview
Grok 4 Fast outperforms in 0 benchmarks, while Hy4 preview is better at 1 benchmark (GPQA).
Hy4 preview significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Context Window
Maximum input and output token capacity
Only Grok 4 Fast specifies input context (2,000,000 tokens). Only Grok 4 Fast specifies output context (30,000 tokens).
Input capabilities
Documented input modalities across available providers
Grok 4 Fast supports multimodal inputs, whereas Hy4 preview does not.
Grok 4 Fast can handle both text and other forms of data like images, making it suitable for multimodal applications.
Grok 4 Fast
Hy4 preview
License
Usage and distribution terms
Grok 4 Fast is licensed under a proprietary license, while Hy4 preview uses Apache 2.0.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
Apache 2.0
Open weights
Release Timeline
When each model was launched
Grok 4 Fast was released on 2025-08-28, while Hy4 preview was released on 2026-08-28.
Hy4 preview is 12 months newer than Grok 4 Fast.
Aug 28, 2025
1.0 years ago
Aug 28, 2026
1 weeks ago
1.0yr newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Outputs Comparison
Judge for yourself.
Run your own prompts against Grok 4 Fast and Hy4 preview side-by-side, then vote on the output you prefer.
FAQ
Common questions about Grok 4 Fast vs Hy4 preview.