Resources » PDF Basics » What’s a PDF Online Optimizer?

What does it mean when you need to “optimize a PDF”? For most users, they’re looking for ways to reduce the file size without losing the quality. In this post, we’ll explain 4 ways to optimize a PDF so it’s easier to share, store and work with.

4 Ways to Optimize PDFs

illustration of a water drop with 1s and 0s going into a laptop for an article on how to optimize a pdf

PDFs can be surprisingly large files, even though they’re designed to be easily shared (hence their name “portable document format”). This isn’t necessarily a bad thing, but it can make managing, sending, and moving PDF files difficult. To make it easier to work with your PDFs, it’s best to optimize them so they don’t have unnecessarily large file sizes. 

Optimizing a PDF can be a complicated process that involves reducing the bloat of a file without a significant reduction to the quality of the document. You can do some PDF file optimization on your own, but there are also tools available that make this very easy. 

In this article, we’ll be going through how you can optimize your PDF to reduce the file size as much as possible. 

  1.  PDF optimization tools

Tools such as the online PDF compressor reduce the sizes of your PDFs without a significant change to the original file quality. The online PDF compressor doesn’t pixelate your PDF images or alter the legibility of your PDF text. The operations that this program performs aren’t easily done by everyday users like us. 

The file compressor essentially audits your PDF to understand what’s taking up space in the file. It will then look through your PDF and remove unnecessary elements. These elements may be unused embedded files like images, fonts, or hidden objects like Javascript functions. It may also remove comments and other data about the user who created the document. This tool is incredibly useful, as it will reduce the size of your file as much as 50% without any notable changes to the file itself. Make sure that any optimization tool you use is lossless so the data within your PDF won’t be affected. 

  1.  Remove/compress images

Images in a PDF are the most common culprits for bloating file size. This is because images are incredibly complex and hold far more data when compared to text. If you’d like to learn more about how computers compress files, consider checking out our article on zipping files

It’s pretty easy to copy and paste an image into a document, but that document then inherits that image file size. If you copy and paste a high quality 1920x1080p resolution image with a 1 MB file size, for example, into your PDF, your document will be at least 1 MB larger. If your PDF is too large to email or store, consider reviewing the images within the document and deleting/compressing them. 

  1.  Unembed unused fonts

If you’re using several different fonts in a document, that PDF file will contain all of the information about that font — including all possible characters. This isn’t an issue with one or two fonts, but if you’re using a lot of different fonts, particularly in other languages, it can sometimes significantly increase the size of your PDF file. Consider using just a couple fonts when constructing your PDF in a document editor. 

  1. Zip PDF

We mentioned zipping files earlier, but what does this mean? A ZIP file is a compressed folder that contains a lot of information in a smaller file. Anyone can make a ZIP file on their computer and open it up later on (unzipping a file). 

If you’re sending a lot of different PDFs or one particularly large PDF, it can sometimes be useful to ZIP your PDF to make it easier to transport digitally. Email and cloud storage services often have file size limits. ZIP files can circumvent these size limitations by creating a smaller file that still contains the PDF(s) you’re using.


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