xAI silently released Grok 4.3 Beta on April 17, 2026, with no announcement post or press release. The update appeared in the model selector on grok.com and immediately surfaced across iOS and Android apps for users on the SuperGrok Heavy tier at $300 per month. A full rollout is expected in mid-to-late May 2026.
Grok 4.3 Adds Native Video Understanding and Document Generation
The update introduces significant new multimodal capabilities. Grok 4.3 adds native video input and processing, expanding beyond the images and text supported in previous versions. Early testers confirmed that the model can now generate presentation slides directly inside the chat interface, a capability absent from Grok 4.20.
Additionally, Grok 4.3 can generate downloadable PDFs, fully populated spreadsheets, and PowerPoint decks directly from conversation. This positions Grok as a more comprehensive productivity tool beyond traditional chat-based AI assistance.
Technical Specifications Maintain Industry-Leading Context Window
The 16-agent Heavy system and 2 million token context window from Grok 4.20 carry over into 4.3, maintaining the largest context window among Western closed models. xAI attributes improvements to enhanced reasoning depth through longer training runs, though no model card has been published at launch.
The quiet release strategy contrasts with typical AI model launches, generating 227 points and 324 comments on Hacker News despite the lack of official announcement. xAI is currently training Grok 5, targeting a Q2 2026 release.
Key Takeaways
- xAI released Grok 4.3 Beta on April 17, 2026, without public announcement, available to SuperGrok Heavy tier subscribers at $300/month
- New features include native video understanding, presentation slide generation, and document creation (PDFs, spreadsheets, PowerPoint)
- Grok 4.3 maintains the 2 million token context window from version 4.20, the largest among Western closed models
- Full rollout expected mid-to-late May 2026, with Grok 5 training underway for Q2 2026 release