Grok Fast
xAI · lightweight line
Latest: Grok 4.1 Fast · Nov 19, 2025
DiscontinuedOfficially discontinued on May 15, 2026
Days since last release
Days since last release
339
days
Recent gaps
Recent gaps
Grok 4.1 Fast · Nov 2025
61
Grok 4.1 Fast
xAI · Grok Fast line · lightweight
Released November 19, 2025Line discontinued May 15, 2026
Grok 4.1 Fast was released by xAI on November 19, 2025, as a lightweight model in the Grok Fast line.
- Release 2 of 2 in the Grok Fast line.
- Came 61 days after Grok 4 Fast, released Sep 19, 2025.
- The last release before the line was discontinued on May 15, 2026.
No detailed card for this model: we only add numbers published by the maker or by independent benchmarks. Sources: xAI · xAI Docs
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Where the Grok Fast line stands
Grok 4.1 Fast is the current model in this line. The card shows how long it has been since the last release against the line's usual gap and its recent ones — the rhythm, not a date.
Every Grok Fast release
Newest first. See the full line with every card →
- Nov 19, 2025Grok 4.1 Fast · this page
- Sep 19, 2025Grok 4 Fast