Grok 4.21 Multi-Agent release date
ForecastxAIlanguage model
Grok 4.21 Multi-Agent has not been announced. Based on how often xAI ships new versions, our forecast is that it arrives around November 19, 2026, probably between October 30, 2026 and January 3, 2027.
The forecast
| Most likely | November 19, 2026 |
|---|---|
| Window | October 30, 2026 to January 3, 2027 |
| Chance it arrives in that window | About 18% |
| Follows | Grok 4.20 Multi-Agent (out March 31, 2026) |
| Based on | no earlier gap to learn from, so we assume about 75 days |
How we got this
xAI is the maker of Grok 4.20 Multi-Agent. We look at the gaps between its earlier versions (Grok 4.20 Multi-Agent, 2026-03-31) and project the next one. It is a guess from a pattern, not news: the maker has not said Grok 4.21 Multi-Agent exists. This page turns into the launch page, with price and facts, as soon as the model shows up on OpenRouter, Hugging Face or GitHub.
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Predicted automatically by Modelcast. Not affiliated with xAI.