Adding a custom thumbnail to a video in your B12 editor

Learn how to add a custom thumbnail to your videos in the B12 editor

Written by: Madeline B. Last updated: 30th June 2025

If you’re showcasing videos on your website, adding a custom thumbnail helps present your content in a more polished and on-brand way. You can upload a custom thumbnail for YouTube videos using B12’s video gallery section. For uploaded videos, the thumbnail (or “poster image”) will default to the first frame of the file.

Follow the steps below to add or change a video thumbnail in the B12 editor.

1. Log into the B12 Editor

3. Select Website > Pages

4. Navigate to the page where your video is displayed

5. Navigate to the video gallery section

In your B12 editor, go to the page where you'd like to display your video. Locate or add a section that supports video content, such as the Video gallery section.

6. Select your preferred layout

Choose a layout that supports custom thumbnails, such as video-grid-2-col-left-landscape-lg

7. Click Add resource to add a new video, or click an existing resource to update its thumbnail.

8. In the resource editor, click the Image tab to manage your thumbnail settings.

9. Upload or select your thumbnail image

Click Upload image to add a new file from your computer, or select an existing image from your media library. Then click Select and continue.

10. Your thumbnail is now applied

The chosen image will now display as the custom thumbnail for your YouTube video in the gallery layout.

For uploaded videos

If you're uploading a video file (rather than embedding from YouTube), the thumbnail is automatically set to the first frame of the video. At this time, B12 does not support changing the poster image for uploaded videos.