Model Watch · Reviewed

xAI Grok 4.3

Announced Apr 17, 2026Released Apr 30, 2026Reviewed Jun 23, 2026
What they claimed

xAI positioned Grok 4.3 as its most intelligent and fastest model, leading with large gains on real-world agentic tasks, a 1M-token context window, and aggressively lower pricing (roughly a 37-58% cut versus the prior Grok 4 generation). Third-party coverage also reported native video input as a headline capability. Notably, xAI shipped it quietly: the model appeared in the grok.com selector without a dedicated launch post, blog announcement, or release-notes entry.

What shipped

The model is real and live: it is listed on xAI's official model docs and served via the xAI API and Amazon Bedrock. Independent benchmarking (Artificial Analysis) confirms the agentic improvement and the price reduction; the much-touted 'native video input' claim, however, appears only in secondary blogs and is not stated in xAI's official docs or in independent analysis.

The verdict

Grok 4.3 is a genuine, deployed frontier model, but the way it shipped is the story: no official announcement, no blog post, just a quiet appearance in the model picker. The verifiable wins are agentic task performance and a real double-digit price cut, both corroborated independently. The flashier 'native video input' framing is a marketing-grade claim we could not confirm in any official xAI source, so executives should treat it as unverified until xAI documents it. The pattern here — capability shipped faster than documentation — is increasingly common and means buyers must validate claimed features against their own use, not the launch chatter.

Why it matters

A frontier-tier model that is cheaper and more agentic than its predecessor lowers the cost of automating multi-step work, but the silent, under-documented launch is a reminder that vendor claims now outrun vendor documentation.

Sources
  1. xAI Models documentation (official, lists grok-4.3)
  2. Artificial Analysis — xAI launches Grok 4.3 with improved agentic performance and lower pricing