xAI Ships Grok 4.3 Beta Quietly — $300/mo Heavy Tier, Native Video, Still No Memory (April 2026)

xAI rolled out Grok 4.3 Beta inside the grok.com model selector on April 17, 2026, at roughly 9 AM UTC — flagged as "Early Access" and, notably, shipped with no press release, blog post, or model card. The new model is locked to SuperGrok Heavy subscribers at $300/month, and xAI has not disclosed when or if it will reach standard $30/month SuperGrok tiers.

What Happened

Grok 4.3 Beta appeared silently in the grok.com dropdown alongside XChat's launch on the Apple App Store, and a related pair of standalone Speech-to-Text and Text-to-Speech APIs — the same voice stack that powers Grok Voice, Tesla vehicle infotainment, and Starlink customer support. On Hacker News, the release drew roughly 13 points and a handful of comments before falling off the front page — the top reply asked "No model card? No benchmarks? No usage examples? Nothing on the blog since the acquisition?"

The new model retains the 2 million token context window and the 16-agent "Heavy" multi-agent architecture introduced with Grok 4.20 in March, and early testers on r/singularity and Dev.to estimate it carries roughly double the parameter count of Grok 4.20 — positioning it as a stepping stone toward Grok 5's publicly-stated 6-trillion-parameter target. xAI has not confirmed the figure.

Key Details

• Release date: April 17, 2026, approximately 9:00 UTC — appeared in the model selector without any official announcement.
• Pricing: $300/month SuperGrok Heavy only. Standard $30/month SuperGrok subscribers can see the option but cannot access it.
• New capabilities: native video input understanding, PDF generation, PowerPoint deck creation, populated spreadsheet output, and deeper integration with Grok Computer (xAI's autonomous desktop agent).
• Context window: 2 million tokens — unchanged from Grok 4.20, still the largest among Western closed-source models.
• Missing features: no persistent memory between sessions — a capability ChatGPT and Claude have shipped for more than a year.
• Companion launches: XChat on the Apple App Store and standalone Speech-to-Text / Text-to-Speech APIs on the same day.
• General availability: estimated mid-to-late May 2026 for the full rollout; no official timeline published.

What Developers and Users Are Saying

Reaction on Hacker News, Reddit, and developer Twitter split cleanly in two directions. Supporters on r/singularity and r/OpenAI praised the pace — four major Grok updates in roughly seven months — and the document-generation features, which finally close a real gap with ChatGPT and Claude. Detractors hit two recurring points. First, the memory gap: as one Reddit commenter put it, "Grok still lacks a basic memory feature, making the expensive Heavy tier a tough sell for everyday use." Second, the opaque release cadence — the top Hacker News comment asked pointedly about the absence of a model card, benchmarks, or any blog update since the xAI ↔ X.com acquisition consolidation, and drew parallels to Tesla's history of ambitious, slipped timelines.

Security researchers also flagged that Grok continues to respond to prompts that GPT-5.4 and Claude Opus 4.7 refuse — echoing complaints raised during the Grok 4.20 launch and earlier imagery incidents. xAI has publicly said safety-vs-personality is a deliberate design choice.

What This Means for Developers

If you are building on the xAI API, Grok 4.3 Beta is not yet exposed through the standard endpoint — it is an in-product feature on grok.com and XChat today. Developers on SuperGrok Heavy can use it interactively; API access is expected alongside the GA rollout in May 2026. Teams paying $300/month for SuperGrok Heavy primarily for coding workflows should weigh it against OpenAI's new $100/month Pro tier (launched April 9) and Anthropic's Claude Max at $100/month — both of which ship persistent memory and arguably cleaner agent tooling today. The 2M-token context and document generation are Grok's sharpest differentiators; for long-document reasoning and slide-deck generation, it's genuinely competitive.

What's Next

xAI has signaled Grok 4.3 Beta will graduate to general availability in mid-to-late May, at which point it should also land on standard SuperGrok and API tiers. Further out, Elon Musk has publicly targeted Grok 5 with 6 trillion parameters for later in 2026. The company has not said whether a model card for 4.3 will be published before GA, but the quiet rollout suggests we may not see one.

Sources

• PiunikaWeb — xAI rolls out Grok 4.3 beta for SuperGrok Heavy subscribers
• BuildFastWithAI — Grok 4.3 Beta features, pricing, and review
• Hacker News — xAI has Released Grok 4.3 (beta)
• Dev.to / TechSifted — Grok 4.3 Review: What's New
• Phemex News — xAI Launches Grok 4.3 Beta with Enhanced Features
• The Saudi Times — xAI Releases Grok 4.3 Beta with Improved Architecture