Here are 20 useful jQuery plugins for showing modal dialogs that can be used to display alert popups, form, videos, and images gallery in a website.

Slick Modal

It is a great way to display your message. You can insert any code or layout inside it, let it be banners, newsletter signups, contact forms, special offer display, images, galleries, iframe, video, maps and more effectively and with style.

Replete Modal

User-friendly, fully customizable, responsive jQuery popup modal to take any HTML content, including images, videos, SVG icons,forms and display it in a clean organised and responsive popup. It is easy, flexible, powerful to create professional looking popup modal.

Modaal

An accessible dialog window library for all humans.

jQuerymodal

A simple & lightweight method of displaying modal windows with jQuery.

Remodal

Responsive, lightweight, fast, synchronized with CSS animations, fully customizable modal window plugin with declarative configuration and hash tracking

animatedModal

jQuery plugin to create a fullscreen modal with CSS3 transitions. You can use the transitions from animate.css or create your own transitions.

Bootbox

JavaScript library which allows you to create programmatic dialog boxes using Bootstrap modals, without having to worry about creating, managing or removing any of the required DOM elements or JS event handlers.

Flying Popup

Allows to show floating HTML popups that follow page scroll/resize (also static HTML popups can be shown when desired). Popups can fly in from outside of the screen (from every direction).

plainModal

The simple jQuery Plugin for fully customizable modal windows. It has basic functions only, and it does not style. It has no image files and no CSS files. Just one small file.

Popup Overlay

jQuery plugin for responsive and accessible modal windows and tooltips.

OmniWindow

Extremely customizable modal window plugin for jQuery with 150 lines of code, written specially for programmers.

Avgrund

jQuery plugin for modal boxes and popups. It uses interesting concept showing depth between popup and page. It works in all modern browsers and gracefully degrade in those that do not support CSS transitions and transformations.

Reveal

This is awesome because it’s easy to implement, is cross-browser compatible with modern browsers (with some graceful degradation of course) and lightweight coming in at only 1.75KB. What that means for you is that it’s fast, sexy and just works.

Magnific Popup

This is a responsive lightbox & dialog script with focus on performance and providing best experience for user with any device.

Simple

This jQuery plugin provides you a shiny and accessible modal window, using ARIA.

VenoBox

The big difference compared to many others modal-window plugins is that VenoBox calculates the max width of the image displayed and preserves its height if is taller than the window
(so in small devices you can scroll down the content, avoiding vertical microscopic resized images).

Vex

A modern dialog library which is highly configurable and easy to style.

Impromptu

It is an extension to help provide a more pleasant way to spontaneously prompt a user for input. More or less this is a great replacement for an alert, prompt, and confirm. Not only does it replace these but it also allows for creating forms within these controls. This is not intended to be a modal replacement, just a quick tool to prompt user input in a fashionable way.

Custombox

Modal Window Effects with transitions CSS3.

Popup

A barebones, flexible jQuery popup plugin. Designed for developers, it’s simple to use but very powerful.