Grok Model Release Timeline: Every Grok Version, with Elon Musk’s Own Words (2023–2026)
Live timeline · last updated · 1 entry in the update log
A dated list of Grok releases built from xAI’s news pages and developer release notes, with Elon Musk’s posts about upcoming versions quoted word for word and linked to the original post on X, so you can compare what was said with what shipped.
As of Oct 21, 2026 the newest Grok model is Grok 4.7, released Sep 21, 2026; Grok 4.8 has been described by Elon Musk on X but has no official release, and the xAI models page lists no grok-4.8 model.
Read on 2026-10-21: x.ai/news pages for each Grok release listed, the xAI developer release notes and models page, and each quoted Elon Musk post, fetched by post id through the X API and compared character by character. Post dates are in UTC. We quote only complete sentences and do not paraphrase inside quotation marks.
Timeline
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xAI announces Grok, an early beta it says had about two months of training, with real-time knowledge of the world through the X platform.
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xAI releases the base model weights and architecture of Grok-1, a 314 billion parameter Mixture-of-Experts model, under the Apache 2.0 license.
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Grok-1.5 is introduced with long-context understanding and improved reasoning, for early testers and existing Grok users on X.
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Grok-2 and the smaller Grok-2 mini are released in beta on X, with API access promised later that month.
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Grok 3 is introduced, which xAI says was trained on its Colossus supercluster with 10x the compute of previous state-of-the-art models.
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Grok 4 launches for SuperGrok and Premium+ subscribers and in the xAI API, together with Grok 4 Heavy in a new SuperGrok Heavy tier.
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Grok 4 Fast is released as a cost-efficient reasoning model with a 2M token context window.
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Grok 4.1 is released on grok.com, X and the mobile apps, focused on creative, emotional and collaborative conversations.
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The xAI release notes record that Grok 4.20 and Grok 4.20 Multi-agent are live in the API.
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Grok 4.5 is announced, priced at $2 per million input tokens and $6 per million output tokens.
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Grok 4.5 starts powering Grok on grok.com, on X and in the iOS and Android apps.
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Elon Musk posts: “Grok 4.6 releases around August 7. This will be the 1.5T model with significantly improved SFT & RL.” In the same post: “Grok 4.7 will be the 2.1T model released a few weeks later.”
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Musk posts: “And Grok 4.6 comes out in a week”.
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Grok 4.6 is released, five days after the “around August 7” date Musk had given.
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Musk replies: “Worth trying Grok 4.6. Fable 5 is smarter overall, but Grok is much faster and lower cost. Grok 4.7 has a good chance of exceeding all current models in intelligence.”
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Grok 4.6 becomes generally available on Amazon Bedrock at $2 input, $0.50 cached input and $6 output per million tokens, with a 500k context window.
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Musk posts: “Grok 4.7 comes out in 10 days”.
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Musk posts: “Grok 4.7 needs a few more days to cook.” He adds: “We might have penalized response length too much (or something) in RL, as it still gives up on hard tasks (that it can do!) too early and isn’t yet sufficiently rigorous in checking its work.”
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Musk posts: “Grok 4.7 should be roughly on par with Opus 5.0, not 5.1. Better in some ways, worse in others. We need to fix multimodal performance. Grok 4.8 will be a noticeable improvement. Grok 4.9 is probably Astra/Fable class. Grok 5 maybe better than anything. We shall see.”
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Grok 4.7 is released. SpaceXSI’s post reads: “Grok 4.7 is here. It's a notable improvement over Grok 4.6 at the same price and speed.”
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Musk posts: “However, most @Bot requests are pretty simple and will be handled by a lightning-fast version of Grok 4.8 when that comes out.”
How the quotes were checked
Every sentence in quotation marks above was copied from the text the X API returned for that exact post id, and each node links to the post. We kept the original punctuation. Where a post continued past what the API returned, we quote only the complete sentences. Musk’s posts are statements of plans, not release notes, so the official release nodes cite xAI pages instead.
Comparing the two is the useful part. On July 28, 2026 Musk wrote that Grok 4.6 would release “around August 7”; xAI’s Grok 4.6 page is dated August 12. On September 2 he wrote “Grok 4.7 comes out in 10 days”, on September 11 that it “needs a few more days to cook”, and Grok 4.7 shipped on September 21, nineteen days after the first post.
Grok 4.8 is the open case. Musk’s September 14 post said it would finish training “this week and start RL”. As of October 21, 2026, about five weeks later, the xAI models page lists grok-4.6 and grok-4.7 but no grok-4.8. That shows only that no release has been published yet, not how long the remaining work will take.
What Musk said about model sizes
Musk has given parameter counts on X that xAI’s announcement pages do not repeat. On July 28 he called Grok 4.6 “the 1.5T model” and said Grok 4.7 “will be the 2.1T model”. On September 14 he wrote: “Grok 4.8, which is a 2.5T model trained with our new C++ software stack, will finish training this week and start RL”. Treat these as his statements, not as specifications xAI has published.
The same day he described the training software: “Our training (aka pre-training) software is now the internally developed C/C++ stack, which was written primarily by the Starlink software team. This is awesome and probably best in industry.” He added: “However, our reinforcement learning stack is still somewhat of a legacy pile of many different third-party software systems. This will get fixed, but isn’t yet.”
Other quotes on Grok 4.6 and 4.7
- July 30, 2026: “And Grok 4.6 is a significant improvement” (post).
- August 17, 2026: “Grok 4.6 is smart, super fast & affordable” (post).
- August 18, 2026: “Try Grok 4.6! Grok 4.7, which is a major upgrade, is coming soon.” (post).
- September 30, 2026: “Grok 4.7 rank 1 on AA cyber index” (post).
- October 7, 2026: “Operating principle is to give Grok Bot users the best possible combination of speed & intelligence.” (post).
- October 8, 2026: “Grok 4.7 ranks first in legal matters” (post).
Gaps in the official record
xAI’s news index has no announcement pages for Grok 4.2, 4.3 or 4.4. The developer models page lists grok-4.20 and grok-4.3 model names, and the release notes date Grok 4.20 and Grok 4.20 Multi-agent to March 10, 2026, but we found no dated official announcement for Grok 4.3, so it has no node above. We add one when we find an official date.
After Grok 4.6 launched on August 12, xAI rolled it out to partner platforms: Amazon Bedrock on August 19, then Google’s and Microsoft’s platforms later in August. Grok 4.7 followed the same path. These are distribution dates, not new models, so only Bedrock is shown as an example.
Which Grok model is the newest
- Released: Grok 4.7, September 21, 2026, at the same price and speed as Grok 4.6 according to SpaceXSI.
- Announced on X but not released: Grok 4.8. As of October 21, 2026 it is not on the xAI models page.
- Mentioned on X only: Grok 4.9 and Grok 5, which Musk described on September 14 without dates.
Related timelines
Our earlier Grok 4.8 timeline tracks the next model in more detail. For the other vendors, see the Claude model timeline, the OpenAI GPT model timeline and the Gemini model timeline. The Front blog index lists every post.
The same format also covers Moonshot Kimi, Mistral, DeepSeek and Alibaba Qwen.
Keep reading on Front
Every post, newest first, is on the Front blog index.
- Grok 4.8: what xAI has actually said: xAI’s Grok 4.5 to 4.7 releases and what has been said about 4.8.
- Claude model release timeline: every Claude version with its release date.
- OpenAI GPT model release timeline: every GPT and o-series model from ChatGPT to GPT-6.
- Gemini model release timeline: every Gemini version from 1.0 to Gemini 4 Argon.
- AI model releases in 2024: the 2024 nodes from the vendor timelines, in date order.
- AI model releases in 2025: the 2025 nodes from the vendor timelines, in date order.
- AI model releases in 2026: the 2026 nodes from the vendor timelines, in date order.
- DeepSeek model timeline: DeepSeek from V2 to V4.1, with API names and licenses.
FAQ
What is the latest Grok model?
Grok 4.7, released September 21, 2026. Grok 4.8 has been described by Elon Musk on X but had not been released as of October 21, 2026.
When is Grok 4.8 coming out?
There is no official date. On September 14, 2026 Musk wrote that Grok 4.8 would “finish training this week and start RL”; on October 7 he referred to a fast version of Grok 4.8 “when that comes out”.
How big is Grok 4.7?
Musk wrote on July 28, 2026 that Grok 4.7 “will be the 2.1T model”. xAI’s Grok 4.7 page is the official source for its specifications.
When was the first Grok released?
xAI announced Grok on November 3, 2023 as an early beta.
Update log
- — First published. Checked x.ai/news, the xAI developer docs and Elon Musk’s X posts through Oct 21, 2026 (UTC+8).