Clients seem to love popups despite their pitfalls (SEO, accessibility, etc.). If you need to indulge them, here are a few good options.
Whether you need a popup that happens automatically after page load or on button press, this is the best modal popup plugin that I’ve found and it’s probably the “industry standard” for WordPress.
You can create popup themes to customize padding, shadow, background opacity, and many other parameters. You can put any content in the popup that would normally go in a WordPress page or post.
Note, I did find a conflict when triggering a popup during Divi Slider animation from one slide to another, but there is an easy CSS fix from the developer.
Divi Overlays (paid plugin, part of Divi Life)
Wow, really good-looking, flexible, and easy-to-use popup maker for Divi. These have really nice background and animation options, much more so than typical popup plugins. Not free, but super useful. I did find a bug where a CSS class would not trigger an overlay; I created a ticket and they had a new build back to me in fewer than 24 hours (turned out it was related to Divi’s big performance theme update). Another time I found a bug where the second popup on a page wouldn’t trigger and they gave me a fix in less than 12 hours!
Please leave your comments or questions below! – Brian