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How to Increase the Size of the Lightbox Popup

In this article we will show you how to increase the lightbox (popup) window size. This solution is useful when the lightbox looks too small or tight for the content displayed in it.

Classic SharePoint experience
Modern SharePoint experience


This article is for you if

  • You use SharePoint classic or modern experience.
  • You have ShortPoint installed on your SharePoint site(s).
  • You are a ShortPoint user with an active license.


You can override the lightbox dimensions by adding some custom CSS. Please follow the steps below.

Open ShortPoint Theme Builder. Click Customize my site:

Navigate to Utilities > Custom CSS:

Copy the code below:

.mfp-iframe-holder .mfp-content {
  max-width: 90vw;
  height: 90vh;
Note: Number 90 in the code means 90% of the screen width / height. You can adjust this number to suit your needs.

Paste it to the Custom CSS field:

Click Apply (1) and then Publish (2) to save your changes:


Here is how the opened lightbox (popup) window looks now:

That's it. Happy customizing.

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