xAI is an artificial intelligence company founded in 2023 and best known for Grok, its family of AI models and assistant. Its stated mission is to accelerate human scientific discovery and build AI that helps people understand the universe. In February 2026, SpaceX acquired xAI, so it now operates within SpaceX.
xAI at a glance
- Announced: July 2023
- Founder: Elon Musk, with a team of engineers from leading AI labs
- Flagship product: Grok, on grok.com, iOS, Android, and X
- Infrastructure: the Colossus GPU supercluster
- Developer access: the xAI API and docs.x.ai
What is xAI?
xAI is a frontier AI lab that builds its own models, trains them on its own infrastructure, and ships them as products. Most people meet it through Grok, the assistant. Developers meet it through the API. Businesses evaluate it for coding, support, and agent workflows.
How did the Grok model family evolve?
Grok launched in November 2023 as an assistant with a witty style and real-time knowledge through X. Each release since then added a new capability: longer context, vision, stronger reasoning, tool use, and developer access.
| Date | Milestone | Why it mattered |
|---|---|---|
| July 2023 | xAI announced | Set the mission to understand the universe |
| November 2023 | Grok launched | First assistant, powered by Grok-1 |
| March 2024 | Grok-1 open release | Weights of a 314B-parameter mixture-of-experts model released under Apache 2.0 |
| March and April 2024 | Grok-1.5 and Grok-1.5V | 128,000-token context, then image understanding |
| August 2024 | Grok-2 | Better chat, coding, and reasoning |
| November 2024 | Public API beta | Developers could build on Grok |
| February 2025 | Grok 3 | Reasoning trained with large-scale reinforcement learning |
| July 2025 | Grok 4 | Native tool use and real-time search |
What makes Grok different?
- Real-time information: xAI built Grok around live signals from X, and later added search across the web and news.
- A distinct voice: Grok was designed to answer with personality, inspired by The Hitchhiker’s Guide to the Galaxy.
- Reasoning focus: recent models spend more time thinking through math, code, and multi-step problems.
- Breadth: chat, code, images and video through Grok Imagine, and voice.
How does xAI build its models?
xAI built a custom training and inference stack on Kubernetes, Rust, and JAX, designed to keep running when GPUs fail at scale. Its Colossus supercluster, described by the company as 200,000 GPUs built in 122 days, trains its larger models.
Three technical themes come up again and again in its releases: reinforcement learning for reasoning, long context for large documents and codebases, and multimodal models that can read charts, screenshots, and photos.
What can you do with Grok?
- Research: search, summarize, and compare sources, including recent news.
- Coding: write code, explain errors, and draft tests.
- Documents: analyze PDFs, charts, and diagrams.
- Creative work: generate images, video, and voice content.
- Products: build assistants and agents on the xAI API.
Like any generative AI, Grok can make mistakes. xAI’s own FAQ warns that outputs may be inaccurate, so important answers still need human review.
Frequently asked questions about xAI
Who founded xAI?
Elon Musk founded xAI and announced it in July 2023.
Is Grok open source?
xAI released the weights of Grok-1 under Apache 2.0 in March 2024. Its newer models are available through Grok and the API.
Can developers use Grok?
Yes. The xAI API supports chat, function calling, image, video, and voice, with documentation at docs.x.ai.
The takeaway
In about three years, xAI went from an announcement to a full model family, an open-weight release, a public API, and one of the largest training clusters in the industry. Grok is the clearest view of its direction: real-time, multimodal, and built to reason. The best way to judge it is to test it on your own tasks.
