jQuery Explained: The Library That Made JavaScript Bearable

Introduction

In the late 2000s, writing JavaScript meant fighting browsers: the same code behaved differently in Internet Explorer, Firefox, and Safari, and even simple tasks like selecting elements or fetching data took verbose, fragile code. jQuery, released by John Resig in 2006, fixed that with one idea: a small library that smoothed over browser differences and made common tasks short. Its $ function became the most recognised symbol in web development, and at its peak jQuery ran on nearly every major website.

The $ that did everything

jQuery's core is selection plus chaining: pick elements with CSS-style selectors, then do things to all of them in one readable line:

// Hide all paragraphs with class "old", then fade in the new content
$(".old").hide();
$("#new-content").fadeIn();
// Fetch data without reloading the page
$.ajax({
  url: "/api/posts",
  method: "GET",
  success: function (data) {
    console.log(data);
  }
});

Before jQuery, the equivalent code was longer and browser-specific; after it, a beginner could build interactive pages in an afternoon. Its plugin ecosystem added sliders, date pickers, and animations, and its AJAX helper ($.ajax) made the "fetch data without reloading" pattern — the ancestor of today's fetch and the async/await post — mainstream.

The honest trade

jQuery's trade is that the web caught up. Modern browsers standardised, so document.querySelector does what $ did, fetch replaced $.ajax, and frameworks like React and Vue (covered earlier) replaced manual DOM updates with a better model for complex apps. New projects rarely start with jQuery today. But it is far from dead: millions of existing sites, WordPress themes, and legacy systems still run it, and understanding its patterns explains a huge amount of the web's history — and the code you will still meet maintaining older sites.

Takeaway

jQuery made JavaScript bearable by unifying browsers behind a short, chainable $ syntax, and it taught the web AJAX and DOM manipulation at scale. Modern JavaScript absorbed its lessons, which is exactly why new projects moved on — and why reading old code still means reading jQuery.

Originally published at https://practicaldevblog.blogspot.com/2026/10/jquery-explained-library-that-made.html