Grok 4.3 Beta: Developer Guide to xAI's Video, Documents & Voice APIs (2026)

On April 17, 2026, xAI dropped Grok 4.3 Beta for SuperGrok Heavy subscribers — and it landed with three capabilities that change how developers should evaluate the platform. The update adds native document generation (PDFs, spreadsheets, and PowerPoint decks directly from conversation), conversational video understanding, and a pair of standalone voice APIs — Speech-to-Text and Text-to-Speech — with pricing that undercuts OpenAI by 86% and ElevenLabs by 92%. If you have been watching xAI from the sidelines, this release is worth a closer look. If you are actively evaluating voice API providers or building document-generation workflows, it may shift your shortlist entirely. Here is a complete developer breakdown of what changed, what the APIs look like, and where the real gaps remain.

What Is Grok 4.3 Beta and Who Has Access

Grok 4.3 Beta is xAI’s latest model update, currently gated behind the SuperGrok Heavy subscription tier at $300 per month — the most expensive consumer AI plan currently on the market. Full rollout to lower tiers is expected in mid-to-late May 2026.

The $300 price point bundles higher rate limits, priority compute access, and the document and voice features described below. For developers who want access to the standalone voice APIs without a SuperGrok subscription, the STT and TTS APIs are available directly through the xAI API console and billed per-use independently of any subscription tier.

One important caveat: xAI has shared minimal official release documentation for this update. The feature descriptions and benchmarks below are sourced from the official xAI developer docs, the xAI news announcement pages, and secondary technical coverage. As with most early beta releases, independent production verification is advisable before committing to a migration at scale.

Document Generation: PDFs, Spreadsheets, and Slide Decks From Conversation

The most immediately practical feature for business users is Grok 4.3’s ability to generate downloadable, formatted documents directly inside a conversation. This is not a “here is the text, paste it yourself” workflow — the model generates complete output files you can share or submit without additional editing.

Three output types are supported at launch:

• PDF reports: Formatted business reports, research summaries, and client-facing documents with headers, sections, and basic layout. Useful for competitive analysis outputs, meeting briefings, and structured summaries that need to look professional out of the box.
• Excel-compatible spreadsheets: Fully populated tables with data, formulas, and structure ready to open in Excel or Google Sheets. This is particularly useful for financial models, comparison tables, and structured data outputs where manually reformatting an LLM response into a spreadsheet has historically cost significant time.
• PowerPoint-compatible presentations: Slide decks with title slides, content slides, and speaker notes, ready to open in PowerPoint or Google Slides. Building a slide deck from an AI conversation has previously required either a dedicated tool like Gamma or manual reformatting; Grok 4.3 handles this natively in the same context as the LLM.

To use document generation, describe the document you need and explicitly request a downloadable file in your prompt. For example: “Write a competitive analysis covering three SaaS pricing page strategies. Output as a formatted PDF with an executive summary and one section per competitor.” Grok 4.3 will generate and attach the file directly in the conversation thread.

This puts Grok 4.3 in direct competition with Gamma, Notion AI, and Microsoft Copilot’s document generation features — but embedded in the same context as a frontier LLM conversation rather than requiring a separate tool or context switch.