How To Compress A PDF File

Compressing PDF files allows you to send them and store them with greater ease. To learn how to compress PDF files, simply follow our step-by-step tutorials below. For all other information, or if you have further questions, please see our FAQ section at the end of this article.

Note: Only Adobe Pro users with a Pro account subscription will be able to compress PDFs in the Adobe Acrobat DC app, and an unlimited number of times. Free Adobe users, or users without an Adobe account, will have to use the online Adobe free compression tool, and will be limited to 1 (one) PDF compression per day.

How to compress a PDF file in Adobe Acrobat DC

  1. On your desktop, open the Adobe Acrobat DC app
  2. Left-click ‘Tools’ from the top-left of the window
  3. Locate and click on the ‘Optimize PDF’ icon under the ‘Protect & Standardize’ section
  4. From the pop-up window, select which PDF you wish to compress from your documents
  5. Next, click ‘Open’
  6. Above the image, and below the toolbar, left-click the button reading ‘Reduce File Size’
  7. In the next pop-up window, select ‘OK’, keeping the ‘Make compatible with’ option ‘Retain existing’
  8. Rename the PDF in the next window, choose a folder on your computer in which to save it, and then click ‘Save’

How to compress a PDF file via the Adobe website

  1. On your desktop, open your preferred web browser and navigate to the ‘Compress PDF’ page of the Adobe website. Alternatively, click this link.
  2. Once on the page, left-click ‘Select a file’
  3. From the pop-up window, select which PDF you wish to compress from your documents
  4. Next, click ‘Open’
  5. Select which compression size you want for your PDF: ‘High compression’, ‘Medium compression’, Low compression’
    1. Note: the ‘higher’ the compression, the smaller the file size, but the lower the quality
  6. Finally, left-click ‘Compress’ and wait for the online tool to complete the compression of your chosen PDF. Once compression is finalised, click ‘Download’. You will find the compressed document in your ‘Downloads’ folder.

And there you have it! Two foolproof ways to compress a PDF file using Adobe. If you need to compress multiple PDFs and don’t have an Adobe Pro subscription, we recommend you scout the internet for a free PDF compression tool which has no daily limit or price tag attached, such as this one: Small PDF


Why would I want to compress a PDF file?

PDFs, or Portable Document Formats, are files of a type designed and patented by Adobe back in 1992. PDFs were designed so that documents of any size, regardless of whether they were text only or contained a range of media, could be easily contained within one universal document format.

PDFs are used by almost all companies and independent professionals, and are safe, secure formats for sensitive files. They can also be readily transported, hence the acronym’s full meaning. Unfortunately, however, large PDFs may not always be accepted by online forms or email providers. Sometimes, when trying to send a large PDF, we’re told its file size accepts the limits of that particular server.

In situations like this, as well as many others, it’s necessary to reduce the file size of your PDF. In other words, it requires compressing. You may wish to compress a PDF in order to send or store it, or simply to reduce the amount of space it’s taking up on your harddrive. 

Whatever your reasons for wanting to compress a PDF, we’re here to show you how. Simply follow our step-by-step guides above.

Will compressing a PDF file reduce the quality of the file?

Yes. In order to compress a file, the quality naturally must also be reduced accordingly. The degree to which you compress the file will affect the overall file quality. Whilst you may not notice much difference in quality between the original and a ‘Large’ compressed PDF, you will almost certainly notice the difference between an original and ‘Small’ compressed PDF.

How do I decompress a compressed PDF file?

Unfortunately, it is not possible to decompress a compressed PDF file. Unless you have access to the ‘master’ PDF (the original source document), you will be unable to restore the PDF to its original state from the compressed version. Thankfully, however, compressed PDFs should typically be of high enough quality to use in almost every way you would use a normal size PDF. The only problem you may face is when it comes to printing that file.

Can I compress any PDF file?

Yes! Provided the file is not password protected (to which you do not have legal access), or corrupted in some other way, you can compress any PDF file you like, to any degree of compression you so choose.