How to Compress PDF Document on iPhone, iPad and Mac to Reduce File Size

If your PDF document exceeds the size limit when you try to upload or share it, or if you want to save some local storage space, you will need to reduce the file size.

In this guide, we will share some free and easy ways to compress PDF files on iPhone, iPad and Mac. Browse them all and choose the one that suits your needs.

Use the built-in tools to shrink your PDF

First, let’s start by using the PDF compression tools built right into macOS, iPadOS, and iOS.

Preview on Mac

On a Mac, you can easily create a PDF without the need for additional software. While the process is fast, it lacks customization options, especially with regards to the quality and, as a result, the file size of the generated PDF.

In these cases, you may end up with a very large PDF file of several MB. Of course, the better the quality of the document, the heavier the file will end up being.

There are times when quality matters more than file size, but in most cases you’ll probably want a smaller file size, which makes it easier to send via email, for example. Luckily, a relatively unknown feature on your Mac allows you to take an existing PDF file and compress it to reduce its size. Here’s how:

1. Double click the PDF file you want to compress to open it. By default, it should open in preview mode. If not, make sure you open this file using Preview (Right Click > Open With > Preview).
2. In the menu bar, click File, then click Export.
3. Click the “Crystal Filter”drop-down menu.
4. Select Reduce File Size, then click Save. The compressed PDF file will be saved on your computer.

Unfortunately, you don’t have any control over the compression level. In most cases, you probably don’t care, but if you really want to change this, you should explore the other options mentioned below.

Quick actions in the Files app on iPhone and iPad

1. Open the Files app on your iOS or iPadOS device and locate the PDF file.
2. Press and hold a PDF file and choose Quick Actions > Optimize File Size. The Files app will process the PDF file, reduce its size, and save it.

Note. If the Files app hangs while creating a compressed PDF file, force close it and reopen it.

iOS shortcut

You can use the free “Optimize PDF File Size”shortcut that will reduce the size of PDF files on your iPhone or iPad:

1. Get the shortcut from this link.
2. Tap the Optimize PDF File Size shortcut tile, select the PDF in the Files app, and then click Open.
3. The shortcut will reduce the size of the PDF and then ask you where to save that compressed file. Select a location in the Files app and click Open. Depending on the size of the PDF, it may take time for the shortcut to save the file and display the final saved notification.

Important: The above built-in methods will not work for all PDFs. So, if they don’t work for a particular PDF, then you should use the methods listed below.

Use Offline Applications to Reduce File Size

Now let’s talk about iOS and macOS apps that can compress PDF size efficiently. You’ll see plenty of options if you search for “compress PDF”in the iPhone or Mac App Store. Some apps download your PDF online or require payment to work. But the ones mentioned below work offline and are free to use. If you’re going to compress an extremely sensitive PDF, feel free to turn off Wi-Fi and cellular data on your device, and yet these apps will reduce the size of the PDF, ensuring it’s not sent to any external server.

Poppy

Lightweight PDF: This is a simple application that can reduce the size of a PDF file by up to 90%. Using it couldn’t be much easier. Just open the app and drag and drop your PDF into its small window. The application will compress and modify the actual file. Select a PDF file and press Command + I to see the reduced file size.

If Lightweight PDF seems too easy (and it is), use these free PDF compression apps that work offline on your Mac:

PDF Compressor Star: When you open this application, it looks like it was created in 1999! But it works as intended, even on macOS Ventura. Start by dragging the PDF file into its window. Then click the gear icon (settings) and select a compression level. Finally, click “Start”> select the output location and click “Save”.

PDF Converter: many of the tools in this application are paid; however, the one that compresses PDFs is free to use.

PDF Compress+: Drag the file > select PDF compression quality > click “Compress”> select an output folder and click “Compress”again.

PDF Reader: Just like other applications, you can use this to reduce the PDF size according to the compression level you choose.

iPhone and iPad

1. Download and open the PDF it All app and tap Compress PDF.
2. Click “Compression Level”and select “Low”, “Medium”, “High”, or “Super High”.
3. Now click Choose PDF File > My Files & iCloud and select the PDF file in the Files app.
4. Click “Share PDF”and choose an option. To save the compressed file in the Files app, tap Save to Files.

You can use this application for free a certain number of times every day. Also, it works on Mac computers with Apple Silicon.

Use Online Sites to Compress PDF

These sites will upload your PDF to their servers for compression. However, most services claim to delete downloaded PDFs after a few hours. But if in doubt, please read their privacy policy before using them.

iLovePDF

I have been using this website for over four years as it is perfect for almost all of my PDF needs.

Here is how to reduce PDF file on iPhone, iPad or Mac using iLovePDF:

1. Visit iLovePDF.com in a web browser.
2. Add files using the Select PDF Files button.
3. Click Compress PDF.
4. As soon as the size of the PDF file is reduced, it will automatically download and save on your Mac. On iPhone and iPad, tap Download Compressed PDF > Share icon > Save to Files.

Use Adobe Acrobat in the browser

1. Visit the Adobe Compress PDF size page.
2. Click “Choose File”and add the PDF file you want to reduce the size.
3. After the PDF file is downloaded, select the compression level (High, Medium, Low) and click “Compress”.
4. Once compression is complete, click Download. On an iPhone or iPad, tap the Share button and choose Save to Files.

Here’s how you can resize a PDF on iPhone, iPad, and Mac.

Finally, other ways to reduce PDF file size are to use fewer images and get rid of unnecessary pages or blank white sheets from your PDF file. You can use Mac Preview to split a PDF file into smaller parts.