How to Create Thumbnails from PDFs on Android

Create Thumbnails from PDFS

In an age and time where there are too many things to do, and too little time to do them, it is hard to capture the interest of fast processing human beings.

Studies have shown that iconic memory (also known as visual memory, or the memory related to sight) is the fastest among all kinds of sensory memories, hence catching our attention in less than a second. 

Therefore, advertisers try to create eye-catching and visually aesthetic ads to tempt us. PDF files are no different. We simply don’t have the time to peruse an entire book or PDF file to find out if it was worth it or not. This is where thumbnails are needed!


The thumbnail is a term used by graphic designers for a small image representation of a larger file or image. They are low-resolution image representations (miniature previews) of a pdf file. They give you an idea of what to expect and whether the contents of the file may interest you or not.

With social media on the rise, thumbnails are very essential for any content to grab viewers’ attention. And it is used by basically everyone who posts their content online including photographers, videographers, writers, etc.

Thumbnails are generated automatically by search engines, image editing programs, as well as image management programs. The smaller file size of thumbnails is especially useful for mobile browsing. Particularly. The size of the thumbnail is particularly convenient for mobile browsing.


PDF stands for Portable Document Format. It is a file format developed by Adobe Systems for representing documents in a manner that is separate from the original operating system, application, or hardware from where it was created.

A PDF file is designed in a way that allows one to make and fetch a type of document that is ready to print. The length is not limited and can use as much as fonts and images as we want to use.

A total description of 2D documents and installed 3D documents are being recorded in every PDF, to compose the document it has text, pictures, and graphics.

It is a modern and very practical way for people to present and exchange documents. Documents, forms, images, and web pages encoded in PDF can be shown anywhere on any device electronically. They are the most commonly used file types today.

Creation of Thumbnails from PDF

Thumbnails are usually used to recognize or organize pdf pages. It is very usual for applications that display PDFs to make a thumbnail preview of PDF. To generate these thumbnails, android has many applications working on the PDFs in your Android devices. These apps have settings and options or certain codes that help you in creating thumbnails.

A thumbnail for a PDF page is also called a Bitmap image and it has become so popular due to the growth of the internet as we discussed earlier. This file format supports up to 8 bits per pixel, therefore, giving an image the ability to contain 256 distinct colors chosen from the 24-bit RGB color space. It upholds animations as well. It uses the lossless data comprehension technique which reduces the file size without any impact on the quality.

The thumbnail file format was invented by Compuserve for their online service, but they made the specifications publicly available. A thumbnail is a simple form of file compression that removes inefficiencies in data storage without losing data or distorting the image.

Associated Applications and Programs 

There are many applications and programs associated with the creation of thumbnails but a few that are quite popular nowadays are Apple Preview, Adobe Photoshop, Corel Paint Shop Pro, Microsoft Windows Photo Gallery Viewer, PDF Box, Android PDF Viewer, etc.

Zamzar is another helpful website for online file conversion and offers PDF to thumbnail conversion easily on your Android device.

Acrobat and Acrobat Reader also allows you to see the thumbnails of PDF documents, on both 64-bit and 32-bit versions. This feature is generally off by default on the application but you can enable this specific setting in the app’s general settings.

You can use ‘PDFViewCtrl’ to get a thumbnail Bitmap image for each page in a PDF Document when using Android. Or you can render a thumbnail image from a PDF file in ‘PSPDFKit’ for Android.

How to Create Your Thumbnail

Creating a thumbnail is pretty quick and easy using any app available online. Let’s go through the thumbnail creation process using Adobe Photoshop.

  • Take a screenshot of your cover or open a page of your file.
  • Select the foreground colour in your colour palette and change to web colour.
  • Under the image menu, select ‘image size’… and change the width to 122 pixels.
  • Press ok.
  • Under the image menu, select ‘canvas size’… and change the height to 180 pixels.
  • Select the up arrow on the ‘anchor’ option and select foreground on the ‘canvas extension colour’ option.
  • Then press ok.
  • Select ‘save as’ under the ‘file’ menu.
  • Save the file as a PNG file.

Your saved file is now ready to upload.

Sample Code for Generating Thumbnail

Webmasters often create computer codes using software languages to create electronic data and don’t need apps installed in their systems. These codes including Kotlin or Java, etc. are very helpful for people who are familiar with computer languages and would rather create a thumbnail this way than by depending upon applications.

Different Application Programming Interfaces (APIs), which are a set of definitions and protocols for building and integrating application software, can also be used to create thumbnails from PDFs on Android. They are pretty straightforward and require the entrance of simple commands into the system. These codes are also available online for anyone who wants a reference.


Why are thumbnails so important? A good custom thumbnail can make all the difference between capturing people’s attention and staying ignored. A good thumbnail leads a person to click on the pdf file if uploaded online.

If you create a thumbnail out of a PDF file for self-perusal, it is easier to go about the images than electronic documents and the thumbnail makes the file clear and out there in the front. It is a convenience one can get used to.

You can also use page thumbnails to jump quickly to a selected page or to adjust the view of the page. It should be noted though, that page thumbnails increase file size.

All the applications that can be installed and offer a one-click solution for you if you are looking to create thumbnails from your PDF files have made this part of the venture fairly easy and approachable.

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