How many companies use Underscore.js?

TechLeads currently detects Underscore.js on 2,162,231 websites. HTTP Archive's monthly crawl, a separate dataset, detected it on 2,432,464 pages in September 2026.

Who are Underscore.js's biggest competitors?

By number of websites, the largest JavaScript libraries technologies besides Underscore.js are jQuery (38,650,119), jQuery Migrate (15,265,182), core-js (9,046,687), Swiper (6,535,690), jQuery UI (6,342,235).

Which companies use Underscore.js?

Websites using Underscore.js include slate.com, sketchfab.com, variety.com, nam.edu, divi-den.com, phpscriptsmall.com. The full list of 2,162,231 websites can be exported as a CSV for $29.

Underscore.js market share and customers

As of October 8, 2026, Underscore.js is used by 2,162,231 websites in the TechLeads index: 1.7% of all JavaScript libraries detections, the 10th most-used of 357 JavaScript libraries technologies.

2,162,231

websites using Underscore.js

1.7%

share of JavaScript libraries

#10

of 357 in JavaScript libraries

Cite this data

Quoting these numbers? Credit TechLeads with a link to this page.

Citation

TechLeads. "Underscore.js Customers and Market Share." Data as of October 8, 2026. https://techleads.fyi/technology/underscore-js/market-share

HTML link

<a href="https://techleads.fyi/technology/underscore-js/market-share">Underscore.js market share (TechLeads data)</a>

Underscore.js vs competitors in JavaScript libraries

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

Underscore.js usage over time

In HTTP Archive's monthly crawl of public websites, Underscore.js was detected on 2,432,464 pages in September 2026, down 16.4% from a year earlier (peak: 3,510,203). Among the 1,000 most-visited sites, it appeared on 44. 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.

Companies using Underscore.js

slate.com
sketchfab.com · Paris / New York
variety.com · Variety Australia
nam.edu · Social Driver
divi-den.com · Divi Den Pro - WP Den
phpscriptsmall.com · Phpscriptsmall
namle.org · U.S. Media Literacy Week
planetwaves.net
discogs.com · harmonic
espn.com · ESPN.com
24h.com.vn · Tin tức 24h
index.hr · Index.hr

See all 2,162,231 websites using Underscore.js or download the full list as a CSV for $29.

How these numbers are calculated

TechLeads scans public websites and detects Underscore.js from signals in the page HTML, scripts, cookies, HTTP headers and DNS records. Market share is Underscore.js'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.

FAQ

Underscore.js accounts for 1.7% of JavaScript libraries detections in the TechLeads index (2,162,231 websites), which makes it the 10th most-used of 357 JavaScript libraries technologies we track.