A modal window, often referred to simply as a modal, is a user interface that demands interaction from the user before they can return to the system. Unlike regular popup boxes, a modal disables the main window but keeps it visible, with the modal window appearing in front as a child window requiring user action.
While it’s possible to create custom modals from scratch, many developers prefer using pre-built libraries to save time and ensure consistency. In this blog post, I’ll share 10 of the best open-source modal libraries in JavaScript and CSS.
The modal libraries in this list are ranked based on their number of visits over the past year. This ranking reflects the preferences and popularity among the developer community rather than my personal opinions. While I’ve carefully curated this selection, the order is determined by the collective interest and adoption rates of these libraries.
Note that this ranking reflects what most developers are using, but it shouldn’t be the sole factor in your decision. Consider the specific features and complexity of each library to find the best fit for your project’s needs.
Last updated: Jan 01, 2026
1. Simple Modal Window With Background Blur Effect
A simple, lightweight vanilla JavaScript library that lets you create a modal window while blurring the background content to focus your user’s attention on modal content.
2. Minimal Overlay Modal In Pure CSS
modalcss is an ultra-light CSS solution to create a simple, responsive modal window with CSS3 animations. Based on pure CSS and plain html structure, without the need to write any checkbox or radio button tricks used in other pure CSS modal solutions.
3. All-in-One Modal Lightbox Solution For Web Developers – DimBox.js
Just another Pure CSS overlay modal solution without any JS and checkbox & label tricks. Click on the blank area of the background overlay to close the modal.
It supports a variety of content types, including images, galleries, HTML5/YouTube/Vimeo videos, iframe content, AJAX content, inline content, and much more.
4. Simple Responsive CSS-Only Modal Dialog
A simple, responsive modal dialog built using CSS and html checkbox.
5. Lightweight Customizable Modal and Alert Library – SilverBox.js
A tiny JavaScript library for creating highly customizable popups, notifications, prompts, confirm dialogs and modal windows without sacrificing performance or quality.
6. Modern Modal Window With Smooth Zoom Animations
A simple, animated, responsive modal window with smooth zoom animations using CSS3 transitions and transforms.
The parent of the modal box will be animated smoothly with CSS3 transitions and transforms. It’s a nice effect that can be used for collecting user information, for error messages, for login pages, or just about anything else.
7. Advanced Dialog & Modal Plugin For Bootstrap 5 – bs5dialog
A JavaScript plugin to create alert/confirm/prompt popups, loading indicators, toast notifications, and dialog windows using Bootstrap 5 styles.
8. Easy Draggable Vanilla JavaScript Modal Window – JS-Modal
A lightweight, draggable, easy-to-use Vanilla JS modal that displays any DOM element in an overlay on top of the current page.
9. Accessible Modal Dialog With CSS3 Animations
An accessible and CSS3 animated modal component built with JavaScript and a native HTML dialog element.
10. Accessible Fullscreen Modal Popup with Pure CSS/CSS3
A responsive, fullscreen, fully accessible modal popup built with HTML/CSS/CSS3. All CSS. No JavaScript required.
