Bage

Modal windows are interesting way to include extran information on a page. <a href="http://www.onextrapixel.com/2014/06/25/create-modal-windows-that-can-be-morphed-from-anything-with-jquery-adaptive-modal-js/" rel="nofollow ugc">adaptive-modal.js</a> makes it beautiful. You can use this little plugin which uses the same jQuery plugin to creae modal windows easily in any page or post or even on a widget uisng shortcode.
I have also added another functionality into this plugin, which will let you to embed your modal content into your post a page directly.
<h3>Usage</h3>
Upon activation, the plugin will create a custom post type called ‘Modals’. Where you can add your content, which later you can use it on a modal or embed directly into your page or post.
<ol>
<li>[modal]</li>
<li>[block] </li>
</ol>
<h3>modal</h3>
the ‘modal’ shortcode is to create modal windows.
For now the [modal] shortcode comes with four attributes.
id 
Your modal id. eg: [modal id=2]Click here[/modal]
data 
If your modal only going to have just text, you can directly add the content in the shortcode. eg: [modal data=”This is my modal content”]Click here[/modal]. This shortcode is much useful when you want to add a modal window to a word in a paragrap without braking the paragrap.
<pre><code>note: you cannot use both id and data in the same shortcode
</code></pre>
background 
This is to style the link and the modal window background. Have to specify a valid color. eg: [modal id=2 background=”#DDDDDD”]Click here[/modal]
color 
This attribute is to change the color of the link. eg: [modal id=2 background=”#DDDDDD” color=”#000000″]Click here[/modal]
<h3>block</h3>
The ‘block’ shortcode is to embed your modal content into any page or post. It only has one attribute.
id 
id of the modal post type post.
<pre><code>note: both block and modal shortcodes uses the same Modals custom post type.
</code></pre>

Flexible Modals

Flexible Modal is a very simple plugin to add modal windows to your WordPress content using shortcodes.

DmtLo

Wow-Company

Use the free WordPress popup plugin “Modal Window” to quickly and easily create informative popups. Add the text and media you need, insert shortcodes of forms and much more. Change the behavior of the display of modal windows depending on the user’s actions on the page.
The Modal Window is a unique tool for free use. With its help, you can add bright information popup messages to the site, warn visitors about various promotions, or display contact forms to increase conversions. The plugin allows you to set the data display in a modern, interactive format.
Create modal windows and insert any kind of content, from simple text to complex layouts with columns and media.
<h4>Main features</h4>
The WordPress plugin Modal Window will help you quickly get the attention of visitors. Its functionality makes it possible to implement high-quality modal windows for any query.
<ul>
<li>Unlimited Modals: Create as many modal windows as you need without restrictions.</li>
<li>HTML Content Editor: Easily add and format text, images, and other content within your modal windows using a built-in HTML editor.</li>
<li>Floating Button Trigger: Create a stylish floating button to trigger your modal. Customize its position, icon, text, and add eye-catching animations (bounce, pulse, shake, etc.).</li>
<li>Advanced Shortcodes: Includes built-in shortcodes for Video (YouTube/Vimeo), iFrames, Buttons, Icons (Font Awesome 7+), and Column layouts (rows/columns).</li>
<li>Open Triggers: Choose from various triggers: Click, Auto (timer), Hover, Exit Intent, and Scroll events.</li>
<li>Custom Styling: Deeply customize Modal Titles, Close Buttons, Backgrounds, Shadows, and even the Scrollbar style to match your brand.</li>
<li>Responsive Control: Set different widths for mobile devices and hide modals on specific screen sizes (Mobile/Desktop).</li>
<li>WCAG & Accessibility: Improved compliance with ARIA attributes (aria-live, role=”dialog”) for better screen reader support.</li>
<li>Overlay and Esc Key: Allow users to close modal windows by clicking on the overlay or pressing the Esc key.</li>
<li>Import/Export: Easily move your modal window settings between websites.</li>
<li>Show Once (Cookies): Control the frequency of display using cookies to avoid annoying returning visitors.</li>
</ul>
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Discover even more features with the Pro version of the Modal Window plugin, available at <a href="https://wow-estore.com/item/wow-modal-windows-pro/" rel="nofollow ugc">wow-estore.com</a>.
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The free Modal Window plugin is the best tool to create information pop-up blocks quickly and easily. It allows you to display any kind of content on the page. Add and edit text messages, shortcodes of various forms, images, and other media files with its help.
<h4>Included Shortcodes</h4>
Maximize your modal content with these built-in shortcodes: 
* <code>[videoBox]</code> – Insert responsive YouTube or Vimeo videos. 
* <code>[iframeBox]</code> – Embed external web pages or interactive content. 
* <code>[buttonBox]</code> – Create beautiful “Link” or “Close Modal” buttons. 
* <code>[wow-icon]</code> – Add any of the 2000+ Font Awesome icons. 
* <code>[w-row]</code> & <code>[w-column]</code> – Create complex multi-column layouts easily.
<h4>Common use cases</h4>
The free version of the Modal Window plugin is versatile and can be used in various scenarios to enhance your website’s functionality and user engagement.
Promotions and Announcements
<ul>
<li>Special Offers: Display limited-time promotions or discounts to capture visitor interest and drive sales.</li>
<li>Event Announcements: Inform users about upcoming events, webinars, or product launches directly on your site.</li>
</ul>
Lead Generation
<ul>
<li>Newsletter Sign-Ups: Create pop-ups to encourage visitors to subscribe to your newsletter, helping you grow your email list.</li>
<li>Contact Forms: Embed contact forms within modals to make it easy for visitors to reach out to you without leaving the page.</li>
</ul>
Content Display
<ul>
<li>Important Information: Highlight critical updates or information, such as privacy policies or terms of service changes.</li>
<li>Multimedia Content: Showcase videos, image galleries, or other multimedia content in a visually appealing modal window.</li>
</ul>
User Interaction
Surveys and Feedback: Collect user feedback or conduct surveys to gather insights and improve your services.
Navigation and Guidance
<ul>
<li>Site Tours: Guide new users through your website’s features with step-by-step tutorials in modal windows.</li>
<li>Pop-Up Menus: Create additional navigation options with pop-up menus that enhance user experience.</li>
</ul>
<h4>Use with other FREE plugins to maximize your results</h4>
<ul>
<li><a href="https://wordpress.org/plugins/counter-box/" rel="ugc">Counter Box</a> – Quickly and easily create countdowns, counters, and timers with a live preview.</li>
<li><a href="https://wordpress.org/plugins/buttons/" rel="ugc">Buttons</a> – Easily create beautiful, customizable standard, floating, and social sharing buttons. Increase click-through rates and enhance your user experience.</li>
<li><a href="https://wordpress.org/plugins/calculator-builder/" rel="ugc">Calculator Builder</a> – A simple way to create an online calculator.</li>
<li><a href="https://wordpress.org/plugins/floating-button/" rel="ugc">Floating Button</a> – WordPress plugin designed to generate and manage sticky Floating Buttons, capable of performing any defined actions on your website.</li>
<li><a href="https://wordpress.org/plugins/counter-box/" rel="ugc">Herd Effects</a> – Designed to create a “sense of queue” or “herd effect”, motivating the visitors of the page to perform any actions.</li>
</ul>
Try other our plugin for create menu:
<ul>
<li><a href="https://wordpress.org/plugins/floating-button/" rel="ugc">Floating Button</a> – Easily generate and manage sticky floating buttons.</li>
<li><a href="https://wordpress.org/plugins/sticky-buttons/" rel="ugc">Sticky Buttons</a> – Easily create sticky buttons with varying complexity.</li>
<li><a href="https://wordpress.org/plugins/bubble-menu/" rel="ugc">Bubble Menu</a> – Create an awesome circle menu with icons.</li>
<li><a href="https://wordpress.org/plugins/float-menu/" rel="ugc">Float menu</a> – Easily create floating menus with varying complexity.</li>
<li><a href="https://wordpress.org/plugins/side-menu-lite/" rel="ugc">Side Menu</a> – Provide any extra content and functionality with the attention-grabbing side menu.</li>
</ul>
<h4>Support</h4>
Search for answers and ask your questions at <a href="https://wordpress.org/support/plugin/modal-window" rel="ugc">support center</a>

Modal Window – create popup modal window

the only reason I'm giving it a 3* is because it's full of ads and "buy pro version" on almost every option, the basic functionality is decent, but still, too many CTAs

full of ads but it works

WordPress popup plugin for easily creating a popup and modal window with any kind of content and settings.

Flexible Modals vs Modal Window – create popup modal window