Grok 4.3 Beta Opens to Subscribers as Musk Says 1T Flagship Nears Training Completion

Elon Musk-founded xAI is using its Grok series to challenge OpenAI, Google and Anthropic. Grok 4.3 brings long-context processing, document handling and agent capabilities into a subscription service. The release is part of the generative AI industry’s shift from chatbots toward systems that can perform tasks and operate computers, while also reflecting the continued move toward premium pricing tiers for advanced models.

As of July 19, 2026, xAI had opened the Grok 4.3 beta to SuperGrok Heavy users paying $300 a month, with support for a 2-million-token context window and PDF operations. Musk said initial training of the 1T flagship model, with 1 trillion parameters, was expected to finish within five days, or around July 24. xAI also launched Grok Computer, which can execute multistep desktop tasks.