jQuery

jQuery is a JavaScript library released in 2006 that became the standard tool for dynamic websites for many years. It wrapped differences between browsers and offered a simple syntax for selecting HTML elements, animations, event handling and Ajax calls. At its peak, jQuery was loaded on the majority of websites.

Functional scope

With its famous dollar function and CSS class style selectors, developers picked HTML elements and modified them. Plug ins added features like sliders, date pickers or validation. Cross browser bugs from the Internet Explorer era were also mitigated by jQuery, which saved a lot of development time and shaped the web development experience for an entire generation.

Today's relevance

Modern browsers now offer many jQuery features natively, such as querySelector, classList and fetch. Frameworks like React or Vue replace the classic model of direct DOM manipulation. jQuery is therefore less often required in new development. In existing websites, themes and plugins the library is still widespread, which is why knowledge about it remains relevant.

Context in daily marketing

In day to day marketing, jQuery mainly appears in older landing pages, WordPress themes and tracking scripts. When optimising websites, check whether jQuery is still needed or can be swapped for smaller code, because every additional library loaded costs load time. A lean codebase improves PageSpeed scores, conversion and therefore the impact of every campaign driving traffic to the page.