← Back toHTML DOM

Create a range slider

Written byPhuoc Nguyen
Level 3 — Advanced
07 Apr, 2020
Last updated
16 Apr, 2020
This post introduces two popular ways to create a range slider.

1. Use a `range` input

HTML provides a built-in `range` input:
<input type="range" />
It's supported in modern browsers, IE 10 and later. But there're some limitations such as:
  • You can't customize the knob
  • At the time of writing this, the vertical-oriented slider isn't supported in all modern browsers
Jump to the next section if you want to have a customizable slider.
Using the similar technique mentioned in this post, we can check if the `range` input is supported or not:
const isRangeInputSupported = function () {
const ele = document.createElement('input');
ele.setAttribute('type', 'range');
// If the browser doesn't support the `range` input,
// the `type` attribute will be reverted back to `text`
return ele.type !== 'text';

2. Create a customizable range slider

A slider is a combination of three parts: a knob, and two sides located at the left and right of the knob.
<div class="container">
<div class="left"></div>
<div class="knob" id="knob"></div>
<div class="right"></div>
These parts are placed in the same row. The right element takes the available width. So, we can use the following styles to build the layout:
.container {
/* Content is centered horizontally */
align-items: center;
display: flex;

/* Size */
height: 1.5rem;
.right {
/* Take the remaining width */
flex: 1;
height: 2px;
You can take a look at the demo to see the full styles of elements.
This page demonstrates the simplest layout for a range slider

Handle the events

The idea of making the knob draggable is quite simple:
  • Handle the knob's `mousedown` event. The handler stores the mouse position:
// Query the element
const knob = document.getElementById('knob');
const leftSide = knob.previousElementSibling;

// The current position of mouse
let x = 0;
let y = 0;
let leftWidth = 0;

// Handle the mousedown event
// that's triggered when user drags the knob
const mouseDownHandler = function (e) {
// Get the current mouse position
x = e.clientX;
y = e.clientY;
leftWidth = leftSide.getBoundingClientRect().width;

// Attach the listeners to `document`
document.addEventListener('mousemove', mouseMoveHandler);
document.addEventListener('mouseup', mouseUpHandler);
  • When the knob is moving, based on the current and original mouse position, we know how far the mouse has been moved. We then set the width for the left side:
const mouseMoveHandler = function (e) {
// How far the mouse has been moved
const dx = e.clientX - x;
const dy = e.clientY - y;

const containerWidth = knob.parentNode.getBoundingClientRect().width;
let newLeftWidth = ((leftWidth + dx) * 100) / containerWidth;
newLeftWidth = Math.max(newLeftWidth, 0);
newLeftWidth = Math.min(newLeftWidth, 100);

leftSide.style.width = `${newLeftWidth}%`;
There're more small things that aren't listed in this post since you can see them in the demo's source. But I always recommend to cleanup everything when the handlers aren't used:
// Triggered when user drops the knob
const mouseUpHandler = function() {

// Remove the handlers of `mousemove` and `mouseup`
document.removeEventListener('mousemove', mouseMoveHandler);
document.removeEventListener('mouseup', mouseUpHandler);

Use cases

Enjoy the demo!


See also

Questions? 🙋

Do you have any questions? Not just about this specific post, but about any topic in front-end development that you'd like to learn more about? If so, feel free to send me a message on Twitter or send me an email. You can find them at the bottom of this page.
I have a long list of upcoming posts, but your questions or ideas for the next one will be my top priority. Let's learn together! Sharing knowledge is the best way to grow 🥷.

Recent posts ⚡

Newsletter 🔔

If you're into front-end technologies and you want to see more of the content I'm creating, then you might want to consider subscribing to my newsletter.
By subscribing, you'll be the first to know about new articles, products, and exclusive promotions.
Don't worry, I won't spam you. And if you ever change your mind, you can unsubscribe at any time.
Phước Nguyễn