Grok 4 Fast vs Qwen3.8-27B
Qwen3.8-27B significantly outperforms across most benchmarks.
xAI · Alibaba Cloud / Qwen Team · Updated for 2026
Which is better?
Grok 4 Fast outperforms in 0 benchmarks, while Qwen3.8-27B is better at 2 benchmarks (GPQA, Humanity's Last Exam). Qwen3.8-27B significantly outperforms across most benchmarks.
Based on current benchmark, 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 Qwen3.8-27B
- you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
- 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.
Performance Benchmarks
Comparative analysis across standard metrics
Grok 4 Fast outperforms in 0 benchmarks, while Qwen3.8-27B is better at 2 benchmarks (GPQA, Humanity's Last Exam).
Qwen3.8-27B significantly outperforms across most benchmarks.
Arena Performance
Playground indexes and blind 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
Supported data types and modalities
Both Grok 4 Fast and Qwen3.8-27B support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Grok 4 Fast
Qwen3.8-27B
License
Usage and distribution terms
Grok 4 Fast is licensed under a proprietary license, while Qwen3.8-27B 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 Qwen3.8-27B was released on 2026-08-14.
Qwen3.8-27B is 12 months newer than Grok 4 Fast.
Aug 28, 2025
12 months ago
Aug 14, 2026
1 weeks ago
11mo 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 Qwen3.8-27B side-by-side, then vote on the output you prefer.
FAQ
Common questions about Grok 4 Fast vs Qwen3.8-27B.