PDF is an extremely popular format thanks to the fact that it can make your document look exactly like a printed copy. Complex layouts, fonts, colors, high-resolution images—all this makes the PDF format a perfect medium for content-rich documents, such as magazines, brochures, presentations, and reports.
However, once you are tasked with sending your file via email to clients or colleagues, you may quickly find that it’s well over the 20 MB limit set by many email hosting services. In this article, we’ll offer a few tips on how to reduce the file size of your PDF and share the results we got when we tested some of the options.
#1 Compress Your PDF File with Adobe Acrobat
This is the quickest fix for reducing the size of your PDF. Here’s what you need to do:
Go to the All Tools tab > select Compress a PDF > Single file to access the PDF file you want to compress > Select a folder to save your optimized PDF to.
Alternatively, you can use Adobe Online PDF Compressor. It’s a free tool that offers three compression options:
- High Compression (smallest size, lower quality)
- Medium Compression (medium size, good quality)
- Low Compression (almost no quality loss)
We’ve tried this method for a 32 MB PDF file and successfully brought it down to 15 MB with Medium settings! It did affect the image quality, but unless your PDF file is a photo album intended for large screens, your readers won’t see the difference.
#2 Reduce PDF File Size with an Online Compressor
There are numerous online PDF compression tools available on the market. We’ve tested a few popular ones, so you could choose one that fits you best.
iLovePDF
This free tool is extremely easy-to-use. All you have to do is upload your PDF file (upload from Dropbox and GoogleDrive is supported), wait for it to convert, and download the ready file. Much like the Adobe Acrobat tool and other services, it offers three compression options: from mild to extreme. Reduced with the ‘Recommended’ settings, our test file went down from 32 MB to 5.9 MB, which is a fantastic result if you are pressed for a low PDF file size.
SmallPDF Pro
SmallPDF Pro has only two PDF compression profiles: basic and strong, but it gives you the estimation of the resulting file size which is very helpful. With basic conversion settings, the tool reduced the size of the test file from 32 MB to 19 MB. The image quality stayed on par with the original, and it became possible to email the PDF file as an attachment.
The tool is free and has a clean, intuitive interface so you can figure it out in seconds.
PDF2Go
PDF2GO is by far the easiest of the three solutions. Once you upload your PDF file, the tool immediately compresses it and downloads the file automatically. So it literally takes just one click to reduce your PDF file size. Plus, it supports uploading from URL which is a nice bonus.
The tool offers two conversion options and a number of presets ranging from ‘Prepress’ (high quality, 300 DPI) to ‘Insane’ (maximum compression, 20 DPI). With the basic conversion settings, we reduced the test PDF file from 32MB to 5MB. While the images look fine if you don’t zoom in, they are not suitable for large screens or printing out. So we’d recommend selecting a preset with a higher DPI for better results.
#3 Alternative to PDF Compression to Avoid Quality Loss
No matter what tool or method of PDF compression you use, it will affect the quality of images. In some cases, it is totally fine—as long as you don’t need a really high resolution, an average reader of your PDF won’t notice the difference.
However, what can you do if you want to share your PDF without any limitations and preserve the best possible image quality at the same time?
You can try turning your PDF into a flipbook! A flipbook is a digital file format that gives your PDF an interactive viewer and makes it available online as a direct link. Here’s what it looks like:
#4 Compress PDF with Adobe Acrobat Advanced Settings
Finally, if you aren’t happy with the results online PDF compressors produce, you can optimize the PDF manually to decrease its size. It takes a bit more time and a professional PDF editor tool to do this, but you get total control over what actually gets reduced or removed from your PDF file.
PDF Space Usage Audition
Adobe Acrobat has a handy tool that shows you exactly which elements take up space in your PDF file. To access it, go to Tools > Optimize PDF > click Advanced Optimization in the top menu. In the PDF Optimizer dialog box, click Audit Space Usage.
Here’s what the audit has revealed for our test PDF file:
As you can see, 99% of space is taken up by images. But embedded fonts, content streams (texts, vector graphics, comments, etc.) can also be culprits of a large PDF file size. Let’s go over all the options so you know what to do in each case.
Large image size
Removing excessive resolution helps noticeably reduce the PDF file size. In fact, that is what most online PDF compressors do—but when you do it manually, you decide which images get compressed and to which extent.
Heavy embedded fonts
If your main problem is fonts, you can unembed the least used ones (such as Traditional Chinese, Japanese, Korean). If you do this, the text in these languages will be displayed in a substitution font that’s available on the system where the file is viewed.
Hidden objects and user data
Are content streams to blame for the large size of your PDF? ‘Discard Objects’ and ‘Discard User Data’ panels let you remove additional content in your file. The Objects include JavaScript actions, document tags, alternate images, bookmarks. User data are comments, forms, file attachments, and private data of other applications.
However, we’d recommend you to be extra careful about deleting these data as it might affect your PDF accessibility and SEO potential.
That’s it! We hope these tips will help you minimize your PDF successfully while keeping its quality top-notch.
