Upload an alternative thumbnail

A thumbnail is a miniature representation of an image or video, and is used to identify an asset by its contents. If the original asset is a video, the thumbnail is an image of the first frame of that video. By default, a thumbnail is automatically created when you upload an asset.

You can upload an alternative thumbnail for the master file. This is useful if you want to display a specific image, such as a close-up of a particular section, or an eye-catching frame from later in a video. Uploading an alternative thumbnail replaces the original thumbnail rendition and the preview rendition.


If you have a custom task for generating a thumbnail for a video file, uploading an alternative thumbnail will not update this custom rendition.

While the rendition is processing, a mountain icon shows instead of the thumbnail. This icon indicates that the rendition for the asset is not ready. When the media processing engines finish processing the asset, the thumbnail rendition appears.

If it is not possible to create a thumbnail or a medium rendition (for example, if the file type is not supported for the rendition), one of the following default images is used:

  • For audio files (.mp3, .wav)

  • For compressed data files (.zip, .7z)

  • For files for which a preview cannot be produced

To upload an alternative thumbnail:

  1. On the asset details page, click Upload upload and select Upload alternative thumbnail.

  2. In the dialog box, do one of the following;

    • Drag and drop the file you want to upload into the dialog.

    • Click Browse, select the file you want to upload, and click Open.

    The new file is used as the preview on the asset details page and the Assets page.

Do you have some feedback for us?

If you have suggestions for improving this article,