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Mini toolsGrok 4 Fast
By xAI
Model family: Grok
Grok 4 Fast is positioned as the lighter, faster sibling to Grok 4 Heavy within xAI’s latest model lineup. It retains the instruction-following, reasoning, and coding strengths of the core Grok 4 architecture, but is pruned and optimized for performance. The trade-off is shallower reasoning depth and lower accuracy on the hardest benchmarks, but the payoff is rapid response times and much lower serving costs.
The model supports long context, JSON-structured outputs, and function/tool calling, enabling seamless integration into retrieval-augmented generation pipelines, automation frameworks, and interactive agent stacks. Its efficiency makes it suitable for real-time chat assistants, high-traffic customer support copilots, and mobile or edge deployments where latency and infrastructure costs must stay under control.
In practice, teams deploy Grok 4 Fast as the default engine for day-to-day workloads, reserving Grok 4 Heavy for tasks that demand maximum reasoning accuracy. This tiered setup provides both responsiveness and depth across the same Grok ecosystem.
The model supports long context, JSON-structured outputs, and function/tool calling, enabling seamless integration into retrieval-augmented generation pipelines, automation frameworks, and interactive agent stacks. Its efficiency makes it suitable for real-time chat assistants, high-traffic customer support copilots, and mobile or edge deployments where latency and infrastructure costs must stay under control.
In practice, teams deploy Grok 4 Fast as the default engine for day-to-day workloads, reserving Grok 4 Heavy for tasks that demand maximum reasoning accuracy. This tiered setup provides both responsiveness and depth across the same Grok ecosystem.
New
Multimodal
Gen 3
Overview
Grok 4 Fast is xAI’s optimized variant of the Grok 4 family. It delivers the same reasoning backbone as Grok 4 Heavy but tuned for speed and efficiency, with lower latency and cost. It’s designed for high-throughput applications, real-time assistants, and workloads where responsiveness matters more than maximum depth.
About xAI
xAI is an artificial intelligence startup founded by Elon Musk, aiming to understand the universe.
View Company ProfileTools using Grok 4 Fast
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Amr عمرو Amin امين🙏 153 karmaJan 23, 2025@PerplexityLoved the search engine ideas. -
It has everything that I need in one place: ChatGPT, Copywriting templates, AI Images, Audio Transcription.
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Personal top 5 most convenient tools for creating content for website or social media. Writing text and generating images immediately
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i love it i use it to teach me Italian and ukranian and programing ! and it awesome , because it allows you in the free version send many prints of your screen , not having to explain all the errors by typing diferent from gpt that you can only send 3 photos in the free version. i also use grok to study i frist make the exercise in my book then i take a photo of my exercise then i ask it to see if there is any mistake and dissipate my terryble handwriting it understands
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Feels illegal to be this early, quick run with Grok Imagine: great for teaser bits. The image-to-video pass holds up for shorts ~6s loops with decent motion and sound sync. Style range is solid. Access sits behind the Grok sub on mobile, so not fully free and I’d love longer clips!
Last updated: February 4, 2026
