1. Popup Maker
Popup Maker, the successor to Easy Modal, is probably the most popular WP modal window plugin and this is for a reason – it’s packed with features. With it you can create responsive opt-in forms, slide-outs, banner bars, floating stickies, notifications, loading screens, and video lightboxes. The plugin works with the most popular form-building plugins (such as Ninja Forms, Gravity Forms, and Contact Form 7) and list-building software (such as MailChimp, AWeber, InfusionSoft, GetResponse, and more).
The plugin offers a lot in terms of configuration. Thanks to triggers and conditions you can fine tune who sees what and when of your modals. You also have a stats module, so you know which of your popups are performing best.
2. Popup Builder
Popup Builder is another popular WP modal window plugin. It also has a lot of features, and in my opinion in terms of configuration options it offers more than most other plugins. Actually, you can configure almost any aspect of a modal you can think of – not only when to show it, whom and where to show it, but can also fully customize its look and feel. All these are included in the free version. If you want more advanced features, such as iframe, video, random, exit popups, or popup scheduling, you can check the Pro version.
3. Popups – WordPress Popup
If for some reason you don’t like Popup Maker and Popup Builder and are looking for a popup plugin with lots of features, you might want to try Popups – WordPress Popup. It works with all major form-building software such as Gravity Forms, Ninja Forms, Contact form 7 and more, but its main advantage is the numerous filters it offers. Thanks to these filters you can fine tune when, where, and how your popups are shown. The paid version includes more (e.g. integration with MailChimp, Aweber and other mailers, A/B split testing, more display rules, etc.)>
4. Modal Window
Modal Window comes with a somehow moderate featureset in comparison to the other three plugins, but if for some reason you don’t like them or if they are not working with your theme, it’s always nice to have more options. The free version of Modal Window comes with lots of limitations, such as the ability to create only three modals, but for a quick solution with a basic popup functionality, it’s more than okay.
5. Popup by Supsystic
Popup by Supsystic is a great choice if you have lots of mobile visitors because it comes with thirty mobile-ready popup templates. As with the other modal window plugins, this one offers triggers, conditions, and customization features. It also offers some not very common for a free plugin feature, such as social popups, link locks, or A/B split testing.
6. Exit Popup
You don’t often need a big plugin with tons of features you never use. If you are looking for an exit popup plugin and don’t want to install a heavyweight plugin because among other things it includes exit popups as well, try Exit Popup. The plugin does just one thing – shows a popup when your visitors are about to leave the page, but it does it well and doesn’t clutter your WordPress installation with features you are not interested in.
7. SMNTCS Shortcode Popup
SMNTCS Shortcode Popup is another small and sweet plugin you can use mostly for contact form popups. The plugin works well with Contact Form 7, Gravity Forms, TablePress, etc., and similarly to the previous plugin, it does only one thing but it does it well. I’ve used this plugin in the past and have no complaints. There are many more modal window plugins that are not included. It’s quite possible you will like some of them more than the ones on this list. However, the plugins that are included are either the most popular ones or come with some cool useful features. As with any WP plugin, some of these might not work with your theme, so even though it looks like there are tons of modal plugins, in reality your choice might be limited to just one or two of them.
