Grok is an AI assistant and a family of large language models, which are neural networks trained on large amounts of text to understand and generate language. It is made by SpaceX Super Intelligence LLC (SpaceXSI) at x.ai; older milestones on the company page use the name xAI.
People use Grok as a chatbot on the web at grok.com, in iOS and Android apps and on X. It answers with step-by-step reasoning, searches the web and X live with citations, writes and explains code, analyzes files and images, holds voice conversations and generates images and short videos. Developers reach the same models through the API: a program sends a prompt to api.x.ai and receives the model's answer. The API works with existing SDKs, including OpenAI's client library, and also offers voice, image and video models, function calling and web search.
The chatbot is free to try, with a paid SuperGrok subscription for higher limits. The API is billed by usage, per million tokens (a token is a piece of a word), with prepaid credits or enterprise invoicing.