Meta's Muse hits 5 million downloads in 22 days — powered by a massive ad blitz

Meta's Muse crossed 5 million downloads in 22 days, outpacing ChatGPT (56 days), Grok (103), and Claude (492) — fueled by a massive Meta advertising push, Sensor Tower reports.

Verified October 1, 2026

#What happened

Three weeks after launching on September 8, Meta's Muse crossed 5 million downloads in the US, according to a Sensor Tower projection by senior insights analyst Kara Lee — after a 12-day streak at the top of the US App Store's free chart. ChatGPT needed 56 days to reach the same US milestone, Grok 103 days, and Claude 492 days, per the firm.

Sensor Tower notes only 23 apps have ever topped 5 million US downloads within 22 days of launch, and roughly 85% of them are mobile games (Fortnite, Pokémon GO, Candy Crush); the non-gaming exceptions are Disney+ (~20M), HBO Max (~18M), and Threads (~14M) in that window. Muse launched on both iOS and Android but is available only in the US and Canada; Claude and Grok were iOS-exclusive in their first five days.

#The ad engine

Sensor Tower says Meta's own advertising push "has likely played a role" in the rapid adoption. Meta began ramping Muse ad spend on Wednesday, September 16, as downloads spiked 73% day-over-day. Over the two weeks of September 14–27, Muse took the largest share of Meta's house ads — up to 50% of daily house impressions — as Facebook and WhatsApp ceded impression share. Muse ranked among the top 15 brands by US advertising impressions during the week of September 21–27.

#Usage is climbing too

Internal data reviewed by The Information (reported by Storyboard18) shows more than 3 million users now send Muse at least one prompt every week, over 1 million do so daily, and more than 4 million people use it in some form at least once a week.

#Why it matters

The distinction matters: downloads measure reach, not whether the agent becomes a habit. A giant house-ad blitz can fill the top of the funnel fast — but keeping millions prompting weekly is what turns a launch spike into a durable assistant.