Grok 4.8 Release Date: What xAI Has Said, and Where Grok 5 Fits

As of 16 October 2026, Grok 4.8 is not out and xAI has given no date for it: its news page, release notes and grok.com model menu still show Grok 4.7, launched on 21 September 2026, as the newest version of the main Grok model. On versus, the prediction Will Grok 4.8 or a newer version come out by 31 Oct? showed Yes at 17.5p at 07:30 UK time on 16 October 2026, the market's estimate of a 17.5% chance that Grok 4.8 or any later Grok, Grok 5 included, reaches the public by the end of October.

SpaceX said on 2 February 2026 that it had acquired xAI (xAI's post). xAI's sites now say SpaceXSI, short for SpaceX Super Intelligence, and the versus rules say SpaceXAI, the name in its copyright line. This guide is for readers in Great Britain.

Main Grok model launches so far, with dates

Dates are from xAI's news page and developer release notes, read on 16 October 2026:

• 9 July 2025: Grok 4, for SuperGrok and Premium+ subscribers and on the API.
• 17 November 2025: Grok 4.1, for all users of grok.com, X and the Grok apps.
• 10 March 2026: Grok 4.20, live on the API per the release notes, with no launch post.
• July 2026: Grok 4.5, on the API from 8 July per the release notes, with a launch post dated 16 July, and on grok.com, X and the apps from 22 July (xAI's post).
• 12 August 2026: Grok 4.6, in Cursor, Grok Build and the API.
• 21 September 2026: Grok 4.7, in the same places. On grok.com the Expert and Heavy modes are labelled Grok 4.7.

Since then the news page has added Grok Bot posts, a new subscription plan (12 October) and Grok Voice 3.0, a voice model (14 October), but no Grok numbered 4.8 or higher.

What xAI and Elon Musk have said

xAI's own channels say nothing about either model. On 16 October neither its news page (newest post 14 October), release notes (newest entries dated 14 October), model list nor grok.com mentions Grok 4.8 or Grok 5, and its X account, @SpaceXSI, has named no next model in its posts since 18 September.

What exists are Elon Musk's posts on X, statements of intent rather than release dates:

• 24 July 2026: he wrote that Grok 4.6 would come in two weeks and Grok 4.7 in four. xAI announced them 19 and 59 days later.
• 14 September 2026: he described Grok 4.8 as "a 2.5T model trained with our new C++ software stack" that "will finish training this week and start RL", RL being reinforcement learning, a later stage of training, and 2.5T being shorthand usually read as 2.5 trillion parameters. He gave no release date.
• Later on 14 September: he wrote that Grok 4.8 would be a noticeable improvement, named a Grok 4.9 as well and said Grok 5 might beat any model, adding that time would tell. Asked how close Grok 4.8 would come to artificial general intelligence, he replied that this would be Grok 5.

What the 31 October prediction counts

Every market on versus names the source that settles it before you trade. Here it is the company's official information, with reliable news reports as a cross-check. In our own words:

• The number. The name contains Grok and is numbered 4.8 or higher, whatever words surround it, so Grok 4.8 Fast, Grok 4.8 Heavy or Grok 5 would count.
• What does not count. Anything numbered below 4.8, including updates or wider rollouts of Grok 4.7; separately numbered lines such as Grok Imagine, Grok Code Fast and, on our reading, Grok Voice 3.0; and new app or website version numbers.
• Public access. A beta or waiting list that anyone can join is enough; a closed test or invite-only access is not.
• Clear evidence. The company says plainly that the public can use it, or the public really can and its official website names it. Placeholders and wrong labels are not enough.
• The window. From 14:43:59 UTC on 22 September 2026 (15:43:59 BST) to 11:59 pm Eastern Time on Saturday 31 October. New York keeps summer time until 1 November and UK clocks go back on 25 October, so that is 03:59 GMT on Sunday 1 November. The page lists its end as 23:59 UTC on 31 October (23:59 GMT).

Grok 5 has predictions of its own

A public Grok 5 before that cut-off would make Yes the right answer above. Two predictions with later end dates ask about Grok 5 alone, so a Grok 4.8 or 4.9 would not count there:

• Will xAI release Grok 5 to the public by 31 Dec? also accepts a model xAI clearly presents as the generation after Grok 4, with the same public access test. Its cut-off is 11:59 pm Eastern Time on 31 December, which is 04:59 UK time (GMT) on 1 January 2027. The page showed Yes at 44p at 07:30 UK time on 16 October 2026.
• When will xAI release Grok 5? has dates as answers: August 15 and August 31 passed without a Grok 5, so neither can come true, and for December 31 its rules set 05:59 Central European Time on 1 January 2027 (04:59 UK time), though its page lists 31 December as the end date.

Dates and signs to watch

• Any day: the three signs that Grok 4.6 and 4.7 each got on launch day, namely a launch post on the news page, a release notes entry and a post from @SpaceXSI (the Grok 4.7 post went out at 17:17 BST on 21 September), or a new label in the grok.com model menu.
• Through October: xAI has published no schedule for Grok 4.8, and Musk's posts of 14 September gave no date, so the only dated milestone left is a launch itself.
• 31 October to 1 November: the page's end time (23:59 GMT on 31 October), then the rules' cut-off (03:59 GMT on 1 November). With a qualifying public release before then, a Yes contract settles at 100p; with none, a No contract does.

Before you trade

A price runs from 0p to 100p and is the market's estimate of a chance: a winning contract settles at 100p and a losing one at 0p, so you can lose the whole amount you put into a position. Each prediction's page shows its rules and settling source, and our guide on how to verify market rules explains what to check. versus adds a 2% transaction fee on top of the stake and shows it before you confirm, and while a market is open you can sell at the current price.

versus is licensed by the UK Gambling Commission under account 101143, which you can check on the Commission's public register. Positions settle in ordinary money, not cryptocurrency. Safer Play tools, including deposit limits, loss limits, reality checks, time out and self exclusion, sit alongside GAMSTOP. Our Fable 5.2 release date guide covers a similar prediction.

Frequently asked questions

Is Grok 4.8 out yet?

No. As of 16 October 2026, xAI's news page, release notes, model list and grok.com all show Grok 4.7, released on 21 September 2026, as the newest version of the main Grok model.

When is Grok 4.8 coming out?

xAI has not said. Elon Musk wrote on 14 September 2026 that Grok 4.8 would finish training that week and then start reinforcement learning, but he named no release day.

Would Grok 5 count for the 31 October prediction?

Yes, if it reaches the public before the cut-off, since the rules accept any Grok numbered 4.8 or higher. No xAI page dates Grok 5.

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