jQuery

jQuery is the JavaScript library that defined web development for over a decade. In an era of incompatible browsers and a clumsy DOM API, jQuery gave developers one simple, reliable way to select elements, manipulate the page, handle events, animate, and make AJAX requests — with $() as its famous entry point. At its peak it ran on the vast majority of the world's top websites.

Today jQuery is in graceful decline: the browser inconsistencies it smoothed over are gone, native JavaScript absorbed its best ideas (querySelectorAll, fetch, classList), and component frameworks (React, Vue) solved the bigger problem of managing UI state. Yet jQuery still ships on a huge share of existing sites (WordPress, countless enterprise apps, legacy admin panels), so working developers meet it constantly — as code to maintain, understand, and often migrate away from. Knowing jQuery is now a maintenance and history skill more than a build-new-things one.

TL;DR

Quick Example

The jQuery you'll read in legacy code, and its native equivalent:

The native version is barely longer now — which is precisely why jQuery's core rationale evaporated. In 2010 the jQuery version was dramatically shorter and worked across browsers the native code didn't.

Why jQuery Mattered (History Worth Knowing)

Understanding jQuery's decline requires understanding the problem it solved. In the mid-2000s:

jQuery didn't just help developers — it influenced the web platform itself. querySelectorAll (CSS selectors in JS), classList, and fetch are standards-body answers to patterns jQuery proved developers wanted. In a real sense, jQuery won so thoroughly that the browser absorbed it, removing the need for it.

Why It Faded

Two independent forces retired jQuery:

1. The platform caught up. Every marquee jQuery feature has a native equivalent now:

And browser inconsistency — jQuery's core reason to exist — largely vanished with IE's death.

2. Frameworks solved a bigger problem. jQuery is imperative: you manually find elements and change them, and keeping the DOM in sync with your data becomes spaghetti as apps grow. React, Vue, and Svelte are declarative: you describe UI as a function of state, and the framework updates the DOM. jQuery never addressed state management — the actual hard problem of complex UIs — which is why frameworks displaced it for anything app-like, while native JS displaced it for simple interactivity.

Working with jQuery Today

Since you'll meet it in existing code, the practical skills are maintenance and migration:

Common Mistakes

Starting New Projects with jQuery

There's essentially no reason to reach for jQuery in new code. Native JS covers simple interactivity, htmx covers server-driven interactivity, and frameworks cover app-like UIs — all without jQuery's baggage. Adding it to a new project imports a legacy dependency for no modern benefit.

Big-Bang Rewrites

Ripping jQuery out of a large working codebase in one go is high-risk and often unnecessary. Migrate incrementally, file by file, with the site working the whole time — or leave stable code alone.

Imperative DOM Spaghetti (In Any Library)

The deeper lesson of jQuery's decline: manually manipulating the DOM to reflect changing state doesn't scale, regardless of library. Rewriting jQuery spaghetti as vanilla-JS spaghetti solves nothing. If the problem is state complexity, the answer is a declarative approach (React, Vue, Svelte), not different DOM-poking syntax.

Assuming jQuery Plugins Are Free to Replace

Legacy sites often depend on jQuery plugins (carousels, date pickers, validation) as much as jQuery itself. Migrating means finding native or framework replacements for those too — sometimes the harder part of the job.

FAQ

Should I learn jQuery in 2026?

Not as a primary skill for building new things — learn native JavaScript and a framework instead. But learn enough to read it, because you will encounter it constantly in existing codebases (especially WordPress and enterprise apps), and maintaining/migrating jQuery is a real job task. It's a "read and maintain" skill, not a "build new" one.

Is jQuery dead?

Effectively retired for new development, but far from gone — it still runs on a large fraction of existing websites and ships with WordPress. "Legacy but ubiquitous, maintained not chosen" is accurate. It won't disappear for years simply because so much depends on it.

What replaces jQuery?

Depends on the need: native JavaScript (querySelectorAll, fetch, classList) for simple DOM/AJAX work; htmx for server-driven interactivity without a SPA; a framework (React/Vue/Svelte) for stateful, app-like UIs. There's no single "jQuery successor" because jQuery's roles split across these.

Why does WordPress still use jQuery?

Backward compatibility — an enormous ecosystem of themes and plugins depends on jQuery, so removing it would break the web at scale. WordPress has modernized around the edges (the block editor uses React), but jQuery remains in core for compatibility. If you work with WordPress, you work with jQuery.

Is it worth migrating a working jQuery site?

Only with a reason: you're already refactoring, hitting jQuery limitations, want to drop the dependency for performance, or the code has become unmaintainable. Migrating purely for fashion is wasted effort — a stable jQuery site that works is fine. Migrate incrementally when you do.

Related Topics

References