A thumbnail is a small image representation of a larger image, usually intended to make it easier and faster to look at or manage a group of larger images. Graphic designers and photographers typically use this term.
For example, software that lets users manage multiple images often provides a miniaturized version of each image so that they don't have to remember the file name of each image.
A thumbnail also means a small and approximate version of a full-size image or brochure layout as a preliminary design step. This is also referred to as a preview image and is a smaller version of the original image.
If someone has a lot of images to look through, thumbnails can help them find an image they want faster since they don't have to open each file individually.
For example, Adobe's Acrobat Reader lets users show a sequence of thumbnails of viewable pages as a way to navigate among the pages in a PDF document.
Webpages with many pictures, such as online stores with visual catalogs, also often provide thumbnail images instead of larger images to make the page download faster. Then the user controls which images need to be seen in full size.
When searching for images on a search engine, the website will return thumbnail versions of images to make scanning and scrolling through images more accessible.
The thumbnail size can vary depending on the purpose. For example, thumbnail images used to represent several larger images, such as in document management software, can be very small because the focus is only on seeing which image is which.
But thumbnail images shown instead of full-size pictures on websites need to be large enough to be helpful yet small enough to download quickly.
The image format for a thumbnail can be either JPEG, PNG, GIF or WEBP. JPEG is used most often because it's smaller in file size than other image formats; however, exact pixel dimensions can vary.
The following is a list of use cases for thumbnails.
See also: digital asset management, version control, image metadata, image content search, image map
13 Jun 2022