Do you have huge PDF documents? Maybe you want to reduce the size of your PDF files, whether because it’s too large to send as an email attachment, or simply because it’s taking too long to load in your PDF reader.
Fortunately, there’s a wide range of services that can compress your files down to a more manageable size. (How does file compression work?) We’ve selected some of the best below.
Some of these couldn’t get any simpler. Others offer far more options to help you decide how much quality loss (if any) you’re willing to let your PDF files suffer. If there are any other similar, free solutions, please let us know in the comments!
1. Third-Party PDF Tools
Adobe Acrobat PDF Optimizer (Cross-Platform)
If you have Adobe Acrobat installed on your computer, there’s a tool within the application called “PDF Optimizer”. This is one of the best and easiest ways to shrink a PDF document.
To get to this, open your PDF in Acrobat, click Tools > Optimize PDF. A toolbar with a few options will appear just above the PDF.
If you click Reduce Size, Acrobat will apply default settings to your file to attempt to reduce its size.
If you click Advanced Optimization, you’ll have more options to ensure you maintain the quality you need. To help with this, in the Advanced Optimization window, click Audit Space Usage, and you’ll be able to see how much space each kind of element is taking up within the file.
PDF Compressor (Windows)
For ease of use and the ability to bulk compress a large number of PDFs at once, PDF Compressor is a great choice that we’ve covered before. Not only can this program compress thousands of PDFs at a time, but it can also shrink encrypted and protected PDFs, too.
What’s more, this compression is lossless, meaning quality is maintained, despite the file size being smaller.
4Dots Free PDF Compress (Windows)
This freeware application enables you to compress single or multiple PDFs in one fell swoop. You’re also able to compress entire folders of PDFs with just a few clicks of the mouse, even if the PDFs are password protected.
Once you’ve selected which files you want to compress (drag and drop is supported), select the location where you want the smaller files to be saved. Hit Compress and the tool will do all the work for you.
Free PDF Compressor (Windows)
This completely free piece of software is also extremely simple to use. Select the file you want to shrink, hit Compress, then save the smaller file.
In addition, you can choose from five levels of compression, depending on how you want to use the file:
- Low resolution (72 dpi), ideal for screen-view only
- Medium resolution (150 dpi), ideal for an ebook
- High resolution (300 dpi), ideal for printing
- Prepress (300 dpi), ideal for prepress, including color preserving
- Default, ideal for a wide variety of uses
2. Browser PDF Tools
You don’t even need an account to use SmallPDF. Simply head over to the site, add the file, and click Compress PDF. You can then either drag your PDF onto the page, locate the file on your hard drive, or import the PDF from Google Drive or Dropbox. The file will then be compressed automatically. Just click the download button to save the new file to your hard drive.
You’re able to compress two files per hour for free. If you want more, you’ll need to upgrade to the premium version.
The quality of the compressed file won’t be less than 144 dpi. This should make most PDFs small enough to upload or send via email without any problems. And if you’re worried about security, the file is deleted from SmallPDF’s servers after one hour.
If you want more control over the quality of your compressed PDF, try DocuPub’s NeeviaPDF (for files less than 10 MB in size).
To keep things simple, you can choose one of the presets, which range from low compression (for a higher image quality) to maximum compression (for a lower image quality). You’re also given the option to discard certain elements from within your PDF. This includes things like forms, annotations, and page labels, which can unnecessarily increase the size of the file.
How much of the original PDF you want to discard depends on how much space you really need to save.
3. Windows PDF Tools
Windows 10 finally includes an option to print-to-PDF. However, advanced features, like tweaking the quality and size of a document, are not part of this feature. Meanwhile, many PDF printers let you choose quality and compression settings, which can greatly influence the size of your PDF files.
Note that the tools highlighted below require GhostScript to view and handle PDFs.
FreePDF is a classic PDF printer and we highlight it here because it allows you to create your own compression profiles. Once installed (remember that you need GhostScript), you’ll find it listed as part of your Windows printers.
To reduce the size of a PDF document with FreePDF, open it, press Ctrl + P to launch the print dialog, choose FreePDF as your printer, click OK, and wait for the FreePDF dialog to pop up. Here, you can choose from three preset PDF profiles, including eBook, High Quality, and Medium Quality.
To create a custom PDF profile, click Edit Configuration in the top right, choose Profiles, click New, and customize the options available in the Profile editor window. You can change the general quality of your PDF, adjust the default resolution for pictures inside a PDF, or add a watermark to your PDFs.
The default medium quality profile compressed a scanned PDF document of 10 MB to a 1.7 MB PDF file with an acceptable loss in quality.
IrfanView is a lightweight and feature-rich image viewer for Windows. It comes with a range of plugins that turn it into a versatile tool, for example to convert images to different file types, add watermarks to your photos, and batch process images. It also has PDF printing qualities, though not in the classic sense.
Before you can view PDF files with IrfanView, you need to install GhostScript. Then, when you attempt to Save your oversized PDF as a new and smaller PDF file, you’ll see a PDF Settings window next to your Save PDF As… dialog. Under General, you might have to set the Preview of PDF during save operation to not needed, so you can select settings immediately. Then you can adjust compression settings as seen below.
In my test, I chose medium quality for all image types and could reduce the size of a 10 MB scanned PDF document to less than 1 MB. The result was visibly blurred, but perfectly legible.
4. Mac PDF Tools
If you routinely update your Mac’s operating system, you should be able to shrink your PDF without installing any new apps. This is a cool feature in OS X that many people don’t know about.
First, open your PDF in preview. Usually you can just double click the file, but if you have a PDF readers such as Adobe Reader installed, you’ll want to right-click > Open With > Preview). Then click File >Export, and in the Quartz Filter drop-down box, select Reduce File Size.
This only works with large PDF files. Try doing this with a very small PDF (less than a few MB), and these could actually increase in size.
Other than the simple process above, there really isn’t much choice for reputable, free PDF compression tools for Mac users. If you want to control the output quality, etc. of your compressed PDFs, your best bet is to download an app such as PDF Squeezer ($5.99).
This is a relatively low-cost app that enables you to choose from various predefined compression settings, or to choose your own. You can also batch process multiple files at once (including encrypted files).
Which PDF Compression Tools Do You Recommend?
This is only the start of what you can do with your PDFs. From reading the text within images and scanning files for malware, to converting PDFs to other formats and unlocking password protected PDFs, you can find the perfect PDF tool to help you.
Whether you’re dealing with interactive PDFs or large ebooks, PDFs can end up being surprisingly large. Each of the tools above should help with shrinking those files to a much more manageable size.