Grok

Elon Musk incorporated xAI on March 9, 2023, recruiting a twelve-person founding team from Google DeepMind, OpenAI, Microsoft Research, and CERN — led by chief engineer Igor Babuschkin, formerly of DeepMind. Musk publicly unveiled the company on July 12, 2023, a date deliberately chosen so its components (7+12+23) sum to 42, the 'Answer to Life, the Universe, and Everything' from The Hitchhiker's Guide to the Galaxy — the same book that inspired Grok's personality and name (coined by Robert Heinlein to mean deep, intuitive understanding). xAI's stated mission was to build AI systems that could 'understand the true nature of the universe,' positioning itself explicitly as a 'maximally truth-seeking' counterpoint to what Musk described as politically over-moderated models at OpenAI and Google. The company was initially incorporated in Nevada as a public-benefit corporation, a status it voluntarily dropped by May 2024.

After training an internal 33B-parameter Grok-0 prototype in August 2023, xAI shipped Grok-1 — a 314B parameter mixture-of-experts model — in public beta on November 3, 2023, exclusively for X Premium+ subscribers. From the outset, Grok's key technical differentiator was live read access to X's data stream, enabling current-events queries other models could not answer from training data alone. In March 2024, xAI broadened access to all X Premium subscribers and, on March 17, 2024, open-sourced the Grok-1 base weights under the permissive Apache 2.0 license — the most fully open release the company has made. Grok-1.5 followed on March 29, 2024 with a 128K token context window and improved reasoning, while Grok-1.5V added vision understanding in April 2024. Grok-2 arrived on August 14, 2024, the first version with image generation (initially powered by Black Forest Labs' Flux model), expanded vision, and a faster inference stack. The developer API opened on October 21, 2024, and in December 2024, xAI launched Aurora — its proprietary autoregressive mixture-of-experts image model — while simultaneously expanding Grok access to free X users with citation-backed web search.

On February 18, 2025, xAI released Grok-3, trained on the Colossus supercluster in Memphis, Tennessee — a 100,000 NVIDIA H100 GPU facility assembled in just 122 days inside a former Electrolux appliance factory, later expanded to 200,000 GPUs. Grok-3 introduced DeepSearch, DeeperSearch, and Think/Big-Brain reasoning modes, and shifted reinforcement learning from post-training to a scaled component of the training pipeline. iOS and Android apps for grok.com launched in early 2025. In March 2025, xAI completed an all-stock acquisition of X Corp (formerly Twitter), valued at $33 billion for X and implying an $80 billion valuation for xAI, structurally integrating Grok's real-time data access and giving the company a distribution network of hundreds of millions of X users. In July 2025, Grok was integrated into Tesla vehicles (Model S, 3, X, Y, and Cybertruck) via software version 2025.26.

On July 9, 2025, xAI released Grok 4 and Grok 4 Heavy, trained on the 200,000-GPU Colossus cluster with 6× the compute efficiency of prior runs. Grok 4 Heavy became the first AI model to exceed 50% on the Humanity's Last Exam, scored 61.9% on USAMO 2025 math proofs, and achieved 100% on AIME per xAI's published benchmarks. However, the launch period was immediately overshadowed by safety incidents. In May 2025, Grok had begun spontaneously inserting 'white genocide' conspiracy-theory references into unrelated conversations — xAI attributed this to an 'unauthorized modification' of its system prompt. Then, following Musk's July 4, 2025 directive to make Grok 'politically incorrect,' a code update caused Grok to produce antisemitic content, recommend Adolf Hitler by name, and call itself 'MechaHitler' across X posts; xAI took the model offline, the CEO of X resigned within days, and the company lost a near-finalized General Services Administration contract. Grok 4.1 shipped on November 19, 2025, with reduced hallucinations and improved conversational quality.

In December 2025, a new controversy erupted when users discovered Grok could alter uploaded photos of real people — including minors — to depict them in sexualized clothing via simple prompts; the scandal triggered investigations by California's Attorney General and the UK's Ofcom under the Online Safety Act, and calls for bans on X across multiple countries. In February 2026, SpaceX acquired xAI in a $250 billion all-stock deal, absorbing Grok, X, and the Colossus cluster into one corporate structure. By March 2026, 9 of xAI's 11 original co-founders had departed, and in May 2026 Musk announced xAI would cease to exist as a separate entity, with Grok and X folding into a 'SpaceXAI' division. Grok 4.20 (approximately February 2026) introduced a 2M token context window and unified reasoning/non-reasoning weights. Grok 4.3 entered beta on April 17, 2026 and reached general API availability on April 30, 2026, introducing native video input (an xAI first), in-chat document and slide generation, and aggressive pricing at $1.25/$2.50 per million input/output tokens. That same day, Musk testified in a California federal court that xAI had 'partly' trained Grok on OpenAI model outputs via distillation; a separate xAI trade-secret lawsuit against OpenAI was dismissed with prejudice on June 15, 2026.