Grok 4

Grok 4 is xAI's flagship model from its July 2025 release, bringing improved reasoning depth and tool use compared to Grok 3. It accepts both text and image input across a 256k token context window, with native integration for web search and external tool invocation, making it strong for agentic systems that need grounding in current data. The model treats tool use as a first-class feature, letting developers build multi-step agents that invoke APIs, run code, and access external data sources. It handles complex reasoning, multimodal analysis, and tasks that need both accuracy and live context. Grok 4 was trained with reinforcement learning at scale on xAI's Colossus cluster. It balances reasoning power with practical performance, positioning it for production agentic applications where reliability matters alongside capability.