Designing Your Series & Episode Thumbnails - Sizes, Guidelines, and Help

Series Thumbnails - Square & Vertical

Series Thumbnails are used to help readers discover your series on the WEBTOON app and website.

Creators need to upload a Square and Vertical Series Thumbnail in order to publish their series.

Square Series Thumbnails

  • Image size must be 1080x1080.
  • Image must be less than 500KB.
  • Only JPG, JPEG, and PNG formats are allowed.

Pro tip: To stay within the file size limit, consider adjusting the image quality! e.g. Photoshop > Save for Web > Change the Quality to 80% (up to 60%)

Square Thumbnail Example_.png

 

Vertical Series Thumbnails

  • Image size must be 1080x1920.
  • Image must be less than 700KB.
  • Only JPG, JPEG, and PNG formats are allowed.

Vertical Thumbnail Example.png

 

Editing Series Thumbnails

Series Thumbnails may be edited at any time. 

To edit your series thumbnail:

  1. Navigate to your Dashboard on the WEBTOON website.
  2. Choose the series you wish to edit, and select ‘Edit’ on the top right.

     


Episode Thumbnails 

Episode Thumbnails appear next to each episode on your series’ Episode List page.

  • Recommended size is 202x142px - rectangular format.
  • Image must be less than 500kb.
  • Only JPG, JPEG, and PNG formats are allowed.
  • File name can only be in English letters and numbers.

Notice: Episode Thumbnails that were not manually modified to these sizes before June 2025 were automatically cropped. If you’re returning to WEBTOON after a break, and have not previously updated the size of your episode thumbnails, you may notice differences in how your episode thumbnails appear.

 

 

Editing Episode Thumbnails

Episode Thumbnails may be edited at any time.

To edit your Episode Thumbnails:

  1. Navigate to your Dashboard. 
  2. Choose the series you wish to edit and select “Edit Episode”.
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