> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://help.kumullus.com/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# Standardize chapter thumbnails

In the **Preferences** tab you can check or uncheck "Automatic generation" in the **Chapter thumbnails** section.

![](https://storage.crisp.chat/users/helpdesk/website/6cd1eb32c6ece00/image_hh464i.png)

The chapter thumbnails correspond to the thumbnails representing each chapter in the introduction screen and in the timeline of the module. 

If you check "Automatic generation", these thumbnails correspond to an automatic capture of the chapter's base video. Like here:

![](https://storage.crisp.chat/users/helpdesk/website/6cd1eb32c6ece00/image_11798s3.png)

If these automatic thumbnails do not suit you, you can uncheck this box, and then the thumbnails will be united as below:

![](https://storage.crisp.chat/users/helpdesk/website/6cd1eb32c6ece00/image_6pj5rm.png)