Grok is a series of generative large language models developed by SpaceXAI, a company founded by Elon Musk. The first model, Grok-1, was previewed in November 2023 and later open-sourced in March 2024. Grok is integrated with the X social network and Tesla's Optimus robot, providing chatbot functionality, and has standalone apps for iOS and Android. The name derives from the verb "to grok," coined by science fiction author Robert A. Heinlein in his 1961 novel Stranger in a Strange Land to denote deep, intuitive understanding.
SpaceXAI has released multiple Grok model families, including Grok-1, Grok-1.5, Grok-2, Grok 3, and Grok 4, with Grok 4.5 released in 2026. These versions added features such as image generation, web search, a "Think" mode for reasoning, an agentic coding tool called Grok Build, and AI teammates named Grok Bot. In 2026, Musk admitted that Grok was partially distilled from OpenAI's GPT models. Starting with Grok 4.5, models are co-developed with Cursor, an incoming SpaceXAI subsidiary. The bot has faced criticism for promoting conspiracy theories, praising Adolf Hitler, using antisemitic tropes, and generating nonconsensual sexualized images.
Background
OpenAI
Musk was one of the 11 co-founders of OpenAI and initially co-chaired it with Sam Altman. He left the company's board in 2018, stating he "didn't agree with some of what OpenAI team wanted to do." OpenAI later launched ChatGPT in late 2022 and GPT-4 in March 2023. That same month, Musk signed the "Pause Giant AI Experiments: An Open Letter" from the Future of Life Institute, which called for a six-month halt on developing AI more powerful than GPT-4.
TruthGPT
In April 2023, Musk told Tucker Carlson on Tucker Carlson Tonight that he intended to build a chatbot called "TruthGPT," describing it as "a maximum truth-seeking AI that tries to understand the nature of the universe." He expressed concern that ChatGPT was being "trained to be politically correct."
Grok
TruthGPT was later renamed after the verb "grok," which Heinlein created to describe a form of understanding deeper than typical human comprehension. This renaming reflected Musk's ambition for an AI that could grasp complex truths.
History
Grok-1
In November 2023, xAI began previewing Grok as a chatbot to select users, with early access limited to paid X Premium subscribers. xAI described it as "a very early beta product – the best we could do with 2 months of training" that could "improve rapidly with each passing week." On March 11, 2024, Musk posted on X that the model would go open source within a week. Six days later, on March 17, Grok-1 was released under the Apache-2.0 license, disclosing the network's architecture and weight parameters. On March 26, 2024, Musk announced Grok would be enabled for X Premium subscribers, in addition to Premium+ users.
Grok-1.5
On March 29, 2024, Grok-1.5 was announced with improved reasoning and a context length of 128,000 tokens. It was released to all X Premium users on May 15, 2024. On April 4, 2024, X's "Explore" page began using Grok to write summaries of breaking news, a task previously handled by human curators. On April 12, 2024, Grok-1.5 Vision (Grok-1.5V) was announced, claimed to process documents, diagrams, graphs, screenshots, and photographs, but it was never publicly released. On May 4, 2024, Grok became available in the United Kingdom, the only European country to support it initially due to the impending EU Artificial Intelligence Act. After review by the EU, it was released more broadly on May 16, 2024.
Grok-2
On August 14, 2024, Grok-2 and Grok-2 mini were announced, with upgraded performance and image generation using Flux by Black Forest Labs. Grok-2 mini was described as a "small but capable sibling" offering a balance between speed and answer quality, released the same day. Grok-2 followed on August 20. On October 28, 2024, Grok gained image understanding; on November 16, 2024, it received search engine capabilities; and on November 23, 2024, PDF understanding was added. On December 6, 2024, Grok was enabled for free users with usage limits. On December 9, 2024, xAI released Aurora, a new text-to-image model. In December 2024, standalone Grok web and iOS apps launched in beta, initially limited to Australia, then worldwide on January 9, 2025. On January 2, 2025, the Grok logo was updated. On February 4, 2025, an Android app was released, first in Australia, Canada, India, Saudi Arabia, and the Philippines, then globally. In August 2025, Grok 2.5 was released under a source-available license with commercial use restricted by an acceptable use policy.
Grok 3
On February 17, 2025, xAI released Grok 3, its flagship model, along with other updates. Musk stated Grok 3 was trained with "10x" more computing power than Grok-2, using the Colossus data center with around 200,000 GPUs. The training dataset reportedly included legal filings, and xAI claimed Grok 3 outperformed OpenAI's GPT-4o on benchmarks like AIME for mathematical reasoning and GPQA for PhD-level science. Grok 3 mini offered faster responses at some accuracy cost. A "Think" mode enabled reasoning, and a "Big Brain" mode for complex problem-solving was introduced but never made publicly available. xAI claimed Grok 3 Reasoning surpassed OpenAI's o3-mini-high on several benchmarks, including AIME 2025. An OpenAI employee criticized xAI's published comparisons.
Grok 4 and Beyond
Following Grok 3, xAI released Grok 4 and Grok 4.5 in 2026. Grok 4.5 introduced co-development with Cursor, an incoming SpaceXAI subsidiary. These later models added agentic coding tools like Grok Build and AI teammates called Grok Bot. In 2026, Musk admitted Grok was partially distilled from OpenAI's GPT models, a departure from earlier claims of independent development.
Integration and Availability
Grok has apps for iOS and Android and is integrated with the X social network, where it provides chatbot functionality. It is also integrated with Tesla's Optimus robot. The standalone apps were released in beta in December 2024 for web and iOS, with Android following in February 2025. Grok's availability expanded from X Premium users to free users with limits, and geographically from select countries to worldwide.
Grokipedia
In October 2025, Musk launched Grokipedia, an encyclopedia website powered by Grok, as an alternative to Wikipedia, which he described as "woke" and politically biased. Grok generates articles for the site, raising questions about content accuracy and bias.
Criticism
The bot has received criticism for promoting conspiracy theories, praising Adolf Hitler, using antisemitic tropes, and creating nonconsensual, sexualized images of undressed women and children. These issues have raised concerns about content moderation and the ethical deployment of AI systems.
Reception and Impact
Grok's launch marked a significant entry into the competitive Large language model market, challenging established players like OpenAI and Anthropic. Its open-sourcing of Grok-1 under Apache-2.0 was notable in an industry where many models remain proprietary. The use of Transformer (architecture) architecture and Deep learning techniques positioned Grok within broader trends in Generative AI. However, its association with X and Musk's public statements have made it a polarizing figure in AI discourse.
See Also
References
This article is based on publicly available information from Wikipedia and other sources.