Facebook and Instagram lost an average of 5 percent of their app downloads year over year in the second quarter of 2026, yet Reels absorbed 51 percent of user time spent on Instagram and more than half of the platform's ad placements over the same period, according to estimates published today by market intelligence firm Sensor Tower.

The data, released on August 3, 2026 and credited to Kara Lee, senior insights analyst at Sensor Tower, covers the three months ended June 30, 2026. All figures are unified and based in the United States unless otherwise noted. The firm compared seven of the largest social networks: Facebook, Instagram, Pinterest, Reddit, Snapchat, TikTok and X.

Two separate stories sit inside the same dataset. One concerns Meta and the degree to which short-form video has reorganised both attention and inventory on Instagram. The other concerns Pinterest, which reports its own second-quarter results later in the earnings season and enters that disclosure with the strongest engagement gains in the cohort, on Sensor Tower's reading.

Installs fall, minutes rise

The download figure is the outlier in an otherwise upward set of numbers. Facebook and Instagram app downloads declined on a year-over-year basis in the second quarter, down an average of 5 percent, per Sensor Tower data.

Time spent moved the other way, and sharply. Instagram led the entire cohort in growth of daily time spent within the app, increasing 12 percent year over year. Sensor Tower notes that this tracks with Meta's own disclosure, which stated that global time spent in the quarter grew double digits year-over-year, largely driven by improvements to Feed and Reelsrecommendations.

The absolute level still leaves room above it. Instagram users averaged 59 minutes per day in the second quarter, trailing only YouTube and TikTok, which averaged 84 minutes per day between them. That gap of 25 minutes is the distance between a photo-and-video hybrid and two products built around video from the start, and Sensor Tower reads Instagram's position in the ranking as evidence of the push toward Reels content.

The combination is worth stating plainly, because the two metrics point in opposite directions. Fewer new installs, more minutes per existing user. Growth in the quarter came from depth rather than reach, at least in the United States market the panel covers.

Reels crosses fifty percent twice

Sensor Tower's central estimate is that over half of user time spent on Instagram, specifically 51 percent, went to Reels in the second quarter of 2026. The firm attributes this to Meta's focus on improving video recommendations.

Reels was also among Instagram's fastest growing surfaces by engagement in the period, up 6 percentage points year over year. That share came out of other surfaces. Instagram user time spent on Stories fell 2 percentage points and time spent on Search fell 1 percentage point over the same twelve months.

The inventory side moved further. Average ads per session within the video section of the app increased by 10 percentage points year over year, surpassing 50 percent of the ad placements on Instagram, per Sensor Tower data. The firm frames this as advertisers increasingly treating Reels as a preferred placement.

A third figure sits underneath both. Average ads per session for app users rose 8 percent year over year in the second quarter, continuing what Sensor Tower describes as substantial increases across the previous three quarters, covering the third quarter of 2025 through the first quarter of 2026.

The distinction between these numbers matters for anyone reading them into a media plan. The 51 percent and the 10 percentage point figures describe composition, meaning how time and placements are distributed inside Instagram. The 8 percent figure describes volume, meaning how many ads a user encounters per session. A platform can shift its mix without raising its ad load, or raise ad load without changing the mix. Sensor Tower's estimates indicate both happened at once.

The Meta numbers behind the estimate

Meta reported its second-quarter results on July 29, 2026, four working days before the Sensor Tower report. Advertising revenue reached $59.36 billion, a 27 percent increase, while net income fell 8 percent to $15.8 billion after a $2.4 billion legal charge and $1.18 billion in severance costs. Ad impressions delivered across the Family of Apps rose 14 percent year over year and the average price per ad rose 12 percent.

Sensor Tower's report title attributes the Instagram ad volume increase to what it calls Meta's Generative Ads Model. The company's own framing during the earnings call was more specific. Meta described a new ranking architecture called the Meta Generative Recommender, which uses large language models to reason jointly about ad content and user preferences rather than scoring each candidate advertisement separately. Early pilots applying language models to user preference understanding produced a 1 percent increase in app event conversions on Instagram. Improvements to user understanding models combined with the GEM ranking system generated an 8.3 percent increase in ad clicks and a 15.7 percent uplift in conversions on Facebook.

Those disclosures concern ranking quality rather than ad load. Sensor Tower's contribution is the volume measurement that Meta does not break out by app: a company-wide impression increase of 14 percent against an estimated 8 percent rise in ads per session on Instagram in the United States.

The trajectory is not new. Meta reported in January 2026 that Instagram Reels watch time increased more than 30 percent year over year in the United States during the fourth quarter of 2025, with Facebook video time also growing double digits. The same period produced $58.1 billion in advertising revenue. A year earlier still, Meta was expanding its AI recommendation model to new surfaces and reporting roughly 5 percent more ad conversions on Instagram.

Pinterest enters earnings with the cohort's strongest engagement gains

Sensor Tower's second set of estimates concerns Pinterest, which had not yet reported second-quarter results at the time of publication.

Daily active users increased 11 percent in the United States and 16 percent globally, year over year. Sensor Tower states that Pinterest experienced the strongest gains in user engagement across the broader social media cohort in the period.

Engagement depth followed the user count. Time spent, measured in minutes per day, grew 11 percent year over year, and session count, measured in sessions per day, grew 9 percent. Both figures trail Instagram's growth, which Sensor Tower singles out as the cohort leader on time spent.

The internal distribution of that time has shifted. Pin detail pages, meaning the individual post view, made up 53.4 percent of user time spent on Pinterest in the second quarter of 2026, up from 51.1 percent a year earlier. Time spent on the main feed moved in the opposite direction, falling to 19.4 percent from 21 percent. Sensor Tower reads this as users spending more time examining curated recommendations rather than browsing the feed.

That surface migration has commercial consequences that Pinterest itself has documented. More than 72 percent of Pinterest impressions occur across search surfaces, according to the company's first-quarter 2026 earnings presentation, which also disclosed revenue of $1.008 billion, up 18 percent year over year, and 631 million monthly active users. Guidance for the second quarter was set at $1.133 billion to $1.153 billion, representing 14 to 16 percent growth.

Where Pinterest's ad dollars came from

Sensor Tower estimates that Pinterest accounts for approximately 4 percent of advertising spend among the social media cohort it tracks. That share places the platform well behind Meta and TikTok in absolute terms while leaving considerable headroom relative to its engagement growth.

Category composition moved during the quarter. Advertising spend was driven by an increased percentage of spend stemming from the broader shopping category, up 1.8 percentage points year over year, and health and wellness, up 0.9 percentage points.

Shopping category concentration aligns with the product direction Pinterest has taken. The company announced four AI products on June 17, 2026, including a Model Context Protocol server in alpha with named agency and technology partners and a Business Assistant in closed beta. Performance+ campaigns, launched in October 2024, drove 30 percent of lower-funnel revenue by the first quarter of 2026.

Methodology and its limits

Sensor Tower states that its mobile app and digital advertising estimates are based on a proprietary panel and data science models. The firm adds that these may not accurately represent metrics for any individual app or advertiser and should be used for directional trend analysis.

That caveat carries weight for several of the figures above. Panel-derived ads-per-session estimates are not the same object as a platform's reported impression count, and a 51 percent time-spent share measured across a panel is not a company disclosure. The unified United States basis also means the figures describe one market, while Meta's reported impression growth of 14 percent covers every region the Family of Apps serves.

Sensor Tower data has appeared in regulatory analysis as well as trade coverage. The French competition authority cited the firm's figures in its July 2026 opinion on the AI agents sector, when it recorded that OpenAI, Google and Anthropic together held more than 84 percent of the global market.

Why this matters for marketers

Placement composition determines creative requirements. Meta's inventory spans 25 distinct ad placements with different aspect ratio specifications, where Facebook Feed supports 1:1 and 4:5 while Stories and Reels formats demand 9:16. If more than half of Instagram ad placements now sit inside the video section, campaigns weighted toward square or portrait static assets are competing for a shrinking share of the surface.

Measurement definitions have moved in parallel. Meta reduced the engaged view threshold for video advertisements from 10 seconds to 5 seconds in March 2026 and limited click-through attribution to link clicks only, changes that alter how Reels placements report performance independently of any change in performance itself. A rising share of video placements interacts directly with those definitions.

The format question extends beyond Instagram. Meta is testing horizontal video on Instagram for TV, an acknowledgement that the 9:16 ratio at the core of Reels was designed for a phone rather than a television screen. Publisher-side appetite for vertical video has been documented separately: a Media.net survey published in November 2025 found 90 percent of consumers expressing interest in vertical video on publisher sites, with YouTube Shorts leading consumption at 56 percent ahead of TikTok and Facebook at 50 percent each.

Attention does not automatically convert into recall. An Adobe study found that only 17 percent of shoppers remembered an advertisement 24 hours after seeing it, while earlier company research identified short-form video as the top-performing format for driving engagement at 42 percent. Higher ads per session raises the number of exposures without settling what each exposure achieves.

For Pinterest, the surface shift toward pin detail pages narrows where an advertisement can reach a user who is deep in a session. The platform has spent the past two years building tooling around that behaviour, from Top of Search ads to simplified campaign entry points aimed at advertisers with no prior experience. Sensor Tower's estimate of a 4 percent share of cohort advertising spend, set against the strongest engagement growth in that cohort, describes the gap the company will be asked about when it reports.

Timeline

Summary

Who: Sensor Tower, a market intelligence firm, published estimates covering Meta's Instagram and Facebook apps and Pinterest, with the data credited to senior insights analyst Kara Lee. The figures concern advertisers, media buyers and publishers operating on short-form video placements.

What: Estimates showing Reels accounting for 51 percent of user time spent on Instagram and more than 50 percent of the platform's ad placements in the second quarter of 2026, average ads per session up 8 percent year over year, Facebook and Instagram app downloads down an average of 5 percent, Instagram daily time spent up 12 percent to 59 minutes per day, Pinterest daily active users up 11 percent in the United States and 16 percent globally, Pinterest time spent up 11 percent and sessions up 9 percent, pin detail pages at 53.4 percent of Pinterest time spent against a main feed share of 19.4 percent, and Pinterest holding roughly 4 percent of cohort advertising spend.

When: The report was published on August 3, 2026, covering the quarter ended June 30, 2026, and follows Meta's second-quarter earnings release of July 29, 2026 while preceding Pinterest's second-quarter disclosure.

Where: All figures are unified and based in the United States unless otherwise noted, drawn from a cohort of the largest social networks comprising Facebook, Instagram, Pinterest, Reddit, Snapchat, TikTok and X.

Why: Instagram's placement mix has crossed the point where video carries the majority of ad slots, which changes creative specification demands and interacts with measurement definitions Meta revised in March 2026. Pinterest arrives at its own earnings with the cohort's strongest engagement growth and a low single-digit share of cohort advertising spend, a gap between attention and monetisation that the quarter's results will test.