Grok 4.5 Explained: What xAI Actually Announced and Whether You Can Use It

Here is the one thing to know before anything else: Grok 4.5 exists, but you cannot use it, no matter what you pay. Elon Musk confirmed on June 28, 2026 that xAI's next model is running in a private beta with teams at SpaceX and Tesla -- and that is the entire availability story. It is not on X, not on grok.com, not in the Grok apps, and xAI has announced no release date. If you searched for Grok 4.5 and landed on pages describing features you can try today, you were reading stale Grok 4 content with a new number on it. This page covers what is actually confirmed, what is marketing, and what you are really using when you talk to Grok on X.

Key Takeaways

• Grok 4.5 is confirmed but private. It runs only inside SpaceX and Tesla; there is no public access on any plan and no announced release date.
• It is built on xAI's new V9 foundation model, roughly 1.5 trillion parameters -- about three times the size of the architecture behind earlier Grok 4 variants.
• xAI trained it with data from Cursor, a popular AI coding tool, aiming squarely at coding and technical work.
• Musk claims internal tests put it close to or above Anthropic's Opus-class models -- a claim no outside party has been able to verify.
• It is late: the original target was late May 2026, so the project is running about a month behind.
• What you can actually use today: Grok 4.1 (all users) and Grok 4.3 (rolling out across paid tiers since April 30, 2026).

What Is Grok 4.5?

Grok 4.5 is the first Grok built on xAI's next-generation foundation, and that is why it matters more than the modest version number suggests. Previous Grok 4 variants ran on what xAI calls its V8-small architecture; Grok 4.5 moves to the new V9 foundation with roughly 1.5 trillion parameters, about triple the size. Parameters are, loosely, the model's adjustable knobs -- more of them does not guarantee intelligence, but a 3x jump is a genuine generational change, not a tune-up. xAI also added training data from Cursor, the AI coding environment, signaling that coding performance is a priority target. Musk has additionally pointed to improvements in reinforcement learning and the company's "Grok Build" system, and says real-world use inside SpaceX and Tesla is feeding improvements back into the model.

What Can It Do -- and What Is Just a Claim?

Honest answer: nobody outside xAI, SpaceX, and Tesla knows, and you should hold every capability claim to that standard. The confirmed facts are structural -- the V9 foundation, the parameter count, the Cursor training data, the private beta. The performance story rests on one assertion: that internal evaluations show Grok 4.5 performing close to, perhaps beyond, Anthropic's Opus-class models. As TechTimes notes, no third party has access and xAI has not submitted the model to any public benchmark, so the claim cannot be checked. Worth remembering: the competitive bar has also moved -- Anthropic's current flagship is Claude Fable 5, which outperforms its Opus predecessors. Comparing your unreleased model to the previous champion is a time-honored piece of launch theater across the industry.

What You Can Actually Use on X Today

Every Grok you can touch right now is a Grok 4-generation model, and which one depends on your plan. xAI made Grok 4.1 available to all users on X, grok.com, and the mobile apps, and the newer Grok 4.3 -- released April 30, 2026 -- has been rolling out to paid tiers in stages, with the top-end plan served first. Here is the availability picture as of July 4, 2026, per xAI's published plans as tracked by FelloAI:

Note the pattern in that last column. No consumer plan -- not even the $300-a-month one -- includes Grok 4.5, and xAI has not confirmed pricing or tier placement for when it ships.

Should You Care?

Care about the trajectory, not the product -- because there is no product yet. Grok 4.5 signals that xAI has a much larger foundation model working well enough to run inside two demanding companies, and that its next public release will likely be a bigger jump than 4.1-to-4.3 was.

Wait if Grok 4.5 is the thing you want: do not buy a subscription today for a model with no release date. When it ships, expect SuperGrok Heavy first, based on how Grok 4.3's rollout went. Subscribe now only if the current Grok 4.3 already fits how you work -- particularly if you live on X and want an assistant with real-time access to what is happening there. Look elsewhere if you want today's proven frontier capability: Claude Fable 5 is the benchmarked leader you can buy now, Gemini 3.1 Pro is the best value with a real free tier, and OpenAI's GPT-5.6 family is weeks from wide release. Our guides to the best free AI chatbots and which chatbot is worth paying for compare them all in plain terms.

The bottom line: Grok 4.5 is a real, confirmed, probably significant model that exists only behind SpaceX and Tesla's doors. Nothing on your X app changed, no plan gets you access, and every performance claim is currently unverifiable. Check back when it has a release date and an independent benchmark -- until then, your decision set is Grok 4.3 versus everyone else's shipping models.