jQuery 4.0: The Library That Turns 20 and Remains Relevant in 2026

Hello HaWkers, in January 2026 the JavaScript community celebrates a historic milestone: the jQuery library turns 20 years old and, to celebrate, released version 4.0. It seems surreal to talk about jQuery in an era dominated by React, Vue, and modern frameworks, but the numbers tell an interesting story.

Does it still make sense to use jQuery in 2026? Let's explore the history, the new features in version 4.0, and understand why millions of websites still depend on this library.

The History of jQuery

The Problem jQuery Solved

In 2006, developing for the web was a compatibility nightmare.

The scenario before jQuery:

• Internet Explorer 6, 7, and Firefox had completely different APIs
• DOM manipulation required browser-specific code
• AJAX was implemented inconsistently
• Animations required deep knowledge of timers

Example of pre-jQuery code:

// Select element - 2006 code
var element;
if (document.getElementById) {
  element = document.getElementById('myId');
} else if (document.all) {
  element = document.all['myId']; // Old IE
} else if (document.layers) {
  element = document.layers['myId']; // Netscape
}

// AJAX - each browser had its own way
var xhr;
if (window.XMLHttpRequest) {
  xhr = new XMLHttpRequest();
} else if (window.ActiveXObject) {
  xhr = new ActiveXObject('Microsoft.XMLHTTP'); // IE
}

The $() Revolution

John Resig created jQuery with a simple proposal: "Write less, do more".

// The same code with jQuery
var element = $('#myId');

// Simplified AJAX
$.ajax({
  url: '/api/data',
  success: function(data) {
    console.log(data);
  }
});

New Features in jQuery 4.0

Major Changes

Version 4.0 brings significant modernizations after years of development.

Legacy support removal:

• Removed support for IE 10 and earlier
• Deprecated APIs finally eliminated
• Legacy compatibility code removed

Results:

Metric	jQuery 3.x	jQuery 4.0	Reduction
Minified size	87 KB	68 KB	22%
Gzipped size	30 KB	24 KB	20%
Deprecated methods	47	0	100%

New Modern APIs

// jQuery 4.0 with native Promises
$('#button').on('click', async function() {
  const data = await $.ajax('/api/users');
  $('#list').html(renderUsers(data));
});

// Improved ES Modules support
import $ from 'jquery';

// New method for Web Components
$('my-component').shadow().find('.internal');

Compatibility with Modern Tools

// jQuery 4.0 works well with modern bundlers
import $ from 'jquery';

// Working treeshaking - import only what you need
import { ajax } from 'jquery/src/ajax';
import { animate } from 'jquery/src/effects';

// TypeScript types included natively
const element: JQuery<HTMLElement> = $('#app');

Why jQuery Is Still Used

Impressive Numbers

Despite the era of frameworks, jQuery remains ubiquitous.

Usage statistics in 2026:

• 77% of websites still use jQuery
• 94% of WordPress sites depend on the library
• Bootstrap 4.x requires jQuery
• Millions of plugins depend on jQuery

Where jQuery still dominates:

1. WordPress: 43% of the web uses WordPress
2. Legacy corporate sites: Migration is expensive
3. Plugins and widgets: Mature ecosystem
4. Rapid prototyping: Still simpler than vanilla JS
5. CMS integration: Drupal, Joomla, etc.

Legitimate Use Cases

// Add simple interactivity to static sites
$(document).ready(function() {
  // Mobile menu toggle
  $('.menu-toggle').click(function() {
    $('.nav-menu').slideToggle();
  });

  // Smooth scroll for anchors
  $('a[href^="#"]').click(function(e) {
    e.preventDefault();
    $('html, body').animate({
      scrollTop: $($(this).attr('href')).offset().top
    }, 500);
  });

  // Simple form validation
  $('#form').submit(function(e) {
    if ($('#email').val() === '') {
      e.preventDefault();
      $('#email').addClass('error');
    }
  });
});

jQuery vs Modern JavaScript

What Changed in 20 Years

JavaScript has evolved dramatically since 2006.

Element selection:

// jQuery
$('.class');
$('#id');
$('div > p');

// Modern JavaScript (ES6+)
document.querySelectorAll('.class');
document.getElementById('id');
document.querySelectorAll('div > p');

Class manipulation:

// jQuery
$('#el').addClass('active');
$('#el').removeClass('active');
$('#el').toggleClass('active');

// Modern JavaScript
document.getElementById('el').classList.add('active');
document.getElementById('el').classList.remove('active');
document.getElementById('el').classList.toggle('active');

AJAX:

// jQuery
$.ajax({
  url: '/api/data',
  method: 'POST',
  data: { name: 'Jeff' },
  success: function(res) { console.log(res); }
});

// Modern Fetch API
fetch('/api/data', {
  method: 'POST',
  body: JSON.stringify({ name: 'Jeff' }),
  headers: { 'Content-Type': 'application/json' }
})
.then(res => res.json())
.then(data => console.log(data));

When to Use Each

Use jQuery when:

• Maintaining legacy project
• Integration with WordPress/CMS
• Quick prototype without build tools
• Team with jQuery experience
• Specific plugins needed

Use vanilla JavaScript when:

• New projects without dependencies
• Performance is key
• Bundle size matters a lot
• Want full control
• Learning fundamentals

Migrating from jQuery

Migration Strategies

For projects wanting to modernize, gradual paths exist.

1. You Might Not Need jQuery:

// Utility library that gradually replaces jQuery
import { ready, ajax, animate } from 'you-might-not-need-jquery';

ready(() => {
  // Code executed after DOM ready
});

2. Gradual replacement:

// Keep jQuery but use vanilla for new code
const jQueryElement = $('#legacy');
const modernElement = document.querySelector('#new');

// Eventually remove jQuery when no dependencies remain

3. Cash or Zepto (lightweight alternatives):

// Cash - jQuery-like API, 6KB
import $ from 'cash-dom';

$('.element').addClass('active');
$('.element').on('click', handler);

Migration Checklist

Before migrating:

1. Identify all jQuery plugins in use
2. Check if modern alternatives exist
3. Estimate rewriting effort
4. Evaluate if the investment is worth it

During migration:

1. Keep jQuery working
2. Write new code in vanilla JS
3. Gradually replace simple functions
4. Test thoroughly

The Legacy of jQuery

Contributions to the Web

jQuery profoundly influenced web development.

APIs that jQuery popularized and browsers adopted:

• document.querySelector() inspired by $()
• classList inspired by .addClass()/.removeClass()
• fetch() inspired by $.ajax()
• animate() Web API inspired by .animate()

Patterns jQuery established:

1. Method chaining
2. Fluent and expressive APIs
3. Plugins with consistent pattern
4. Exemplary documentation

The Future of the Library

jQuery roadmap:

• Focus on maintenance and security
• Continuous size reduction
• Better ES Modules integration
• Improved TypeScript support
• Web Components compatibility

The jQuery team does not intend to compete with modern frameworks. The goal is to continue being a useful tool for specific use cases.

Conclusion

jQuery turning 20 and releasing version 4.0 is a reminder of how the JavaScript ecosystem has evolved. The library that revolutionized web development in 2006 still finds its place in 2026, albeit in different niches.

Key points:

1. jQuery 4.0 is 22% smaller than version 3.x
2. Removed legacy code and deprecated APIs
3. 77% of websites still use jQuery
4. Modern JavaScript absorbed many ideas from jQuery
5. Migration should be gradual and well-planned

Recommendations:

• New projects: consider vanilla JS or modern frameworks
• Legacy projects: upgrade to jQuery 4.0 for better security
• WordPress: jQuery remains the default choice
• Learning: understand vanilla JS before jQuery

If you want to better understand modern JavaScript that can replace jQuery, I recommend reading: JavaScript and the Future of the Web: Trends to Watch.

Let's go! 🦅