As of October 8, 2026, Intersection Observer is used by 31,697 websites in the TechLeads index: 0.02% of all JavaScript libraries detections, the 107th most-used of 357 JavaScript libraries technologies.
Quoting these numbers? Credit TechLeads with a link to this page.
Citation
TechLeads. "Intersection Observer Customers and Market Share." Data as of October 8, 2026. https://techleads.fyi/technology/intersection-observer/market-shareHTML link
<a href="https://techleads.fyi/technology/intersection-observer/market-share">Intersection Observer market share (TechLeads data)</a>Websites using each technology in the TechLeads index, and its share of all JavaScript libraries detections.
| # | Technology | Websites | Share |
|---|---|---|---|
| 1 | jQuery | 38,650,119 | 29.7% |
| 2 | jQuery Migrate | 15,265,182 | 11.7% |
| 3 | core-js | 9,046,687 | 6.9% |
| 4 | Swiper | 6,535,690 | 5.0% |
| 5 | jQuery UI | 6,342,235 | 4.9% |
| 6 | OWL Carousel | 3,899,597 | 3.0% |
| 7 | Lodash |
In HTTP Archive's monthly crawl of public websites, Intersection Observer was detected on 31,047 pages in September 2026, down 9.8% from a year earlier (peak: 35,588). HTTP Archive is a separate dataset from the TechLeads index, so its numbers are not added to ours.
Same month, other JavaScript Libraries technologies in HTTP Archive: jQuery 32,400,479, core-js 20,296,277, jQuery Migrate 14,931,388, jQuery UI 10,564,965, Swiper 7,844,933.
Based on country-code domains (such as .de or .co.uk); websites on .com and other generic domains are not assigned a country.
See all 31,697 websites using Intersection Observer or download the full list as a CSV for $29.
TechLeads scans public websites and detects Intersection Observer from signals in the page HTML, scripts, cookies, HTTP headers and DNS records. Market share is Intersection Observer's website count divided by the website counts of all JavaScript libraries technologies we track; a site using two JavaScript libraries tools counts for both. Counts were last refreshed on October 8, 2026 and update daily.
| 3,142,449 |
| 2.4% |
| 8 | Slick | 3,093,583 | 2.4% |
| 9 | Popper.js | 2,439,600 | 1.9% |
| 10 | Underscore.js | 2,162,231 | 1.7% |
| 11 | Magnific Popup | 2,055,623 | 1.6% |
| 12 | OwlCarousel2 | 2,010,036 | 1.5% |
| 13 | jQuery Waypoints | 1,818,222 | 1.4% |
| 14 | Moment.js | 1,604,632 | 1.2% |
| 15 | Lightbox | 1,570,437 | 1.2% |
| 16 | Facebook SDK | 1,527,292 | 1.2% |
| 17 | Google Hosted jQuery | 1,498,615 | 1.2% |
| 18 | LazySizes | 1,495,151 | 1.1% |
| 19 | Select2 | 1,405,229 | 1.1% |
| 20 | FancyBox | 1,404,904 | 1.1% |
| 21 | Intersection Observer | 31,697 | 0.02% |
Rows link to each competitor's market share page where one exists. The table lists the 21 most-used technologies; ranks are by website count.