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Technology · Web Development

Underscore.js

underscorejs.org

Underscore.js is a utility-belt JavaScript library that provides a wide array of functional programming helpers without extending any built-in objects. It offers over 100 functions for common operations on arrays, objects, and functions, emphasizing a functional programming style. Underscore.js is known for its consistency across browsers and its ability to complement jQuery in many web applications.

Underscore.js belongs toJavaScript librariescategory.

35websites

use it — 1.4% of the 2,555 websites we scanned in the last 12 months

#24of 108

tools in its category seen in our scans (we recognize 252)

12public pages

on UptimeCard — open any of them to see how that site is doing

0.96% of all websites we track run Underscore.js

At a glance

UptimeCard's own scans and tests of 2,555 websites · refreshed weekly

How Underscore.js sites scoreout of 100 · hover or tap a score for details

43PerformancePooraverage site: 5084AccessibilityGoodaverage site: 8978Best practicesFairaverage site: 9392SEOGoodaverage site: 92

Page load time

Loads about 15% slower than the average site

Underscore.js sites
4.9 s
All sites
4.3 s

Most Underscore.js sites load in 4.2–7.2 s. Home page weight: 3.6 MB vs 3.3 MB for all sites. 8 public sites measured.

Who uses it?

Business Services sites use Underscore.js 3.5× more than average

Technology and Software50%
Business Services3.5× avg42%
Educational Resources8%

Share of 12 classified public sites. “× average” compares with all 961 public sites.

How Underscore.js sites are built

Closest partners. The number says how many times more often the tool runs on Underscore.js sites than on an average website. Hover a partner for its share of sites.

Backbone.js73×Babel12×Moment.js10×Lodash7×Elementor4×Yoast SEO4×Prebid4×Bootstrap3×Funding Choices3×

Stacks we see most. Tools that tend to run together with Underscore.js on the same websites. The percentage is the share of all 35 Underscore.js sites that run the whole stack.

5 stacks · swipe, drag or use the arrows
#1

Underscore.js + Backbone.js + WordPress + Yoast SEO

17.1%6 of 35 sites
#2

Underscore.js + Backbone.js + Bootstrap

20%7 of 35 sites
#3

Underscore.js + Backbone.js + Amazon CloudFront + AWS Certificate Manager

11.4%4 of 35 sites
#4

Underscore.js + WordPress + Elementor + Site Kit

11.4%4 of 35 sites
#5

Underscore.js + Backbone.js + Varnish

14.3%5 of 35 sites

Usually installed alongside

The bigger the bubble, the more of the 35 Underscore.js sites also run the tool. Colour shows what the tool does. Hover or tap a bubble for details.

Google Tag Manager89%Google Analytics66%Facebook Pixel29%Linkedin Insight Tag20%Yoast SEO37%Cart Functionality26%Prebid20%DoubleClick Floodlight17%Microsoft Advertising17%OneTrust20%Funding Choices17%Elementor20%
Tag managerAnalyticsSearch visibilityOnline storeAdvertisingCookie consentPage builder

Similar tools in its category

JavaScript libraries: 252 tools known, 108 seen in our scans

lit-html155 sitesAlternativelit-element128 sitesAlternativeLazySizes114 sitesAlternativeSlick98 sitesAlternativePreact97 sitesAlternativeBoomerang96 sitesAlternativeweb-vitals73 sitesAlternativeModernizr69 sitesAlternativejQuery1,030 sitesUsed togethercore-js776 sitesUsed togetherSwiper285 sitesUsed togetherjQuery Migrate245 sitesUsed together

Websites using Underscore.js

35 websites use Underscore.js: 1.4% of the 2,555 websites we scanned in the last 12 months. A selection is shown below.

Scores are out of 100: P Performance · A Accessibility · B Best practices · S SEO. Green 80+, yellow 65–79, orange 50–64, red below 50. The dot shows whether our last scan found the site failing (red) or not (green); Red, amber or blue: an active incident on the site's status page (outage, degraded, maintenance) or a failing scan; amber also means a certificate ending within 30 days. Hover the dot for details.

Questions about Underscore.js

How many websites use Underscore.js?
We found Underscore.js on 35 of the 2,555 websites we scanned in the last 12 months (1.4%). 12 of them have a public status page.
What is Underscore.js often used with?
Among the websites we scan, Underscore.js is often found alongside Google Tag Manager (88.6% of its sites), Backbone.js (65.7% of its sites), PHP (60% of its sites).
What are the alternatives to Underscore.js?
Other javascript libraries tools we recognize include jQuery, core-js, Swiper, jQuery Migrate.

Is your website built with Underscore.js?

UptimeCard checks it around the clock, tells you the minute it stops answering, and gives your visitors a status page.

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