Grok 4
Released
Grok 4 is an AI model released by SpaceXAI on Wednesday, Jul 9 2025, 142 days after Grok 3 mini.
About
Grok 4, released July 9, 2025, was xAI's reasoning-first flagship, trained with large-scale reinforcement learning on the Colossus cluster. It launched with claims of leading scores on Humanity's Last Exam and ARC-AGI-2, and shipped alongside Grok 4 Heavy, a multi-agent variant that runs several instances in parallel and compares their answers.
The launch cemented xAI's pattern of aggressive benchmark competition and rapid iteration: Grok 4 Fast followed in September 2025, the coding-focused Grok Code Fast 1 in August, and Grok 4.1 in November 2025. The line continued with Grok 4.5 in July 2026 and Grok 4.6 in August 2026.
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Frequently asked questions
Grok 4 was released by SpaceXAI on Wednesday, Jul 9 2025.
Grok 4 was built by SpaceXAI. Elon Musk's AI company building the Grok series of models. Founded in 2023 as xAI, now part of SpaceX. Cursor (Anysphere) and its Composer coding models were acquired in 2026 and are tracked here.
No. Grok 4 is a proprietary model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.
SpaceXAI's previous tracked release was Grok 3 mini on Feb 17 2025, 142 days earlier. It was followed by Grok 4 Heavy on Jul 9 2025.