Model Comparison
Grok 4 Fast vs Qwen3 VL 8B InstructWhich is better in 2026?
Grok 4 Fast significantly outperforms across most benchmarks. Qwen3 VL 8B Instruct is 1.5x cheaper per token.
Verdict: Grok 4 Fast vs Qwen3 VL 8B Instruct — which is better?
Grok 4 Fast (by xAI) and Qwen3 VL 8B Instruct (by Alibaba Cloud / Qwen Team) 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.
Grok 4 Fast outperforms in 1 benchmarks (AIME 2025), while Qwen3 VL 8B Instruct is better at 0 benchmarks. Grok 4 Fast significantly outperforms across most benchmarks.
On price, Qwen3 VL 8B Instruct is roughly 1.5x 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 Grok 4 Fast if…
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- you process long inputs — it offers a 2,000,000 token context window
Choose Qwen3 VL 8B Instruct if…
- cost matters — it's about 1.5x cheaper per token
- you want the most recent training data — it shipped Sep 2025
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
Grok 4 Fast outperforms in 1 benchmarks (AIME 2025), while Qwen3 VL 8B Instruct is better at 0 benchmarks.
Grok 4 Fast significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Grok 4 Fast ($0.20/1M tokens) is 2.5x more expensive than Qwen3 VL 8B Instruct ($0.08/1M tokens).
For output processing, Grok 4 Fast ($0.50/1M tokens) costs the same as Qwen3 VL 8B Instruct ($0.50/1M tokens).
In conclusion, Grok 4 Fast is more expensive than Qwen3 VL 8B Instruct.*
* 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 Qwen3 VL 8B Instruct's 131,072 tokens. Qwen3 VL 8B Instruct can generate longer responses up to 32,768 tokens, while Grok 4 Fast is limited to 30,000 tokens.
Input Capabilities
Supported data types and modalities
Both Grok 4 Fast and Qwen3 VL 8B Instruct support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Grok 4 Fast
Qwen3 VL 8B Instruct
License
Usage and distribution terms
Grok 4 Fast is licensed under a proprietary license, while Qwen3 VL 8B Instruct 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 VL 8B Instruct was released on 2025-09-22.
Qwen3 VL 8B Instruct is 1 month newer than Grok 4 Fast.
Aug 28, 2025
11 months ago
Sep 22, 2025
10 months ago
3w newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Grok 4 Fast is available from xAI. Qwen3 VL 8B Instruct is available from Novita, DeepInfra.
Grok 4 Fast
Qwen3 VL 8B Instruct
Outputs Comparison
Key Takeaways
Qwen3 VL 8B Instruct
View detailsAlibaba Cloud / Qwen Team
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Grok 4 Fast and Qwen3 VL 8B Instruct side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Grok 4 Fast vs Qwen3 VL 8B Instruct.