Elon Musk’s artificial-intelligence company xAI has unlocked its Grok 4 model for free, extending access to all global users via the web and updated iOS and Android apps. The company said the move is temporary but comes with higher usage limits; the more powerful Grok 4 Heavy variant remains reserved for paying SuperGrok Heavy subscribers. The decision follows OpenAI’s public release of GPT-5 earlier this month, intensifying competition among so-called frontier models. Musk signalled that the rapid release cadence will continue, disclosing that Grok 4.20 has finished pre-training and will add native audio- and video-input handling with tone detection. xAI plans to introduce three new foundational models and two upgrades this year, with Grok 5 scheduled for launch before year-end. Despite ChatGPT retaining a 78.5% share of generative-AI web traffic, market-analysis data on 12 August show Grok’s share has climbed to 2.5%. xAI is seeking to accelerate adoption through the free tier and frequent app updates—versions 1.1.44 and 1.1.45 add an enhanced ‘Imagine’ multimedia feature—as it positions Grok against offerings from OpenAI, Google and Anthropic.