Dabuuker

Show content in a modal after page load.
Usage:
Select ‘SN Popup’ from the admin menu, then Add New. Type a name for the popup and insert any content you like. If you’re done, click Publish.
Now find a page or post you’d like to see the popup on and edit it. There should be a new metabox called ‘SN Popup’, choose the settings you want and hit Update, then view your page.
Video: https://www.youtube.com/watch?v=t6lt6v3fuEQ
To change the styling of the modal, you can override its styles in your theme’s css. Or for more advanced styling you can dequeue the default css and replace it with your own.
For reference, the default unminified version of the css is located at /plugins/sn-popup/vendor/featherlight-1.3.4/src/featherlight.css
To dequeue the old css and enqueue your own, add something like this to your functions.php:
<pre><code>add_action('wp_enqueue_scripts','remove_featherlight_css'); function remove_featherlight_css(){ wp_dequeue_style('sn-featherlight'); wp_enqueue_style('featherlight-new-css','/path-to-new-css'); } </code></pre>

Soronet Popup

jaicreator

Image Popup Lite is a free and user-friendly WordPress plugin designed to grab your visitors’ attention with beautiful image popups. Perfect for promotions, announcements, or special offers.
This is the Lite version with essential features. Upgrade to Pro for custom button text, analytics tracking, and priority support.
<h3>Core Features (Lite Version)</h3>
<ul>
<li>✅ Simple On/Off Switch – Enable or disable the popup with a single click.</li>
<li>✅ Easy Image Upload – Uses the native WordPress Media Library for simplicity.</li>
<li>✅ Optimized 16:9 Aspect Ratio – Ensures your image looks professional on all modern screens.</li>
<li>✅ Preset Button Text – Choose from 5 preset button text options.</li>
<li>✅ Button Color Picker – Select the perfect color to match your brand’s style.</li>
<li>✅ Customizable Button Link – Direct visitors to any URL you want.</li>
<li>✅ 100% Responsive – Looks perfect on desktops, tablets, and mobile devices.</li>
</ul>
<h3>Pro Features (Upgrade Required)</h3>
<ul>
<li>⭐ Custom Button Name – Write your own unique call-to-action text.</li>
<li>⭐ Advanced Analytics Tracking – Track popup views, clicks, and conversion rates.</li>
<li>⭐ Priority Support – Get help directly from the developer.</li>
</ul>
<a href="https://www.codester.com/items/59691/wp-image-popup-pro-fast-popup-builder" rel="nofollow ugc">Upgrade to Pro Version →</a>

JaiCreator Image Popup Lite

Free image popup plugin with customizable buttons. Boost engagement easily. Lite version.

Soronet Popup vs JaiCreator Image Popup Lite