How to Compress PDFs for Free

A large PDF can be too big to email, slow to upload and awkward to store. You don't need to buy a PDF app to make it smaller. The methods below use tools that come with Windows or Microsoft Office, and one for Mac users. Start with the first one that fits your file, and check the size after each step.

1. Check How Big Your PDF Is

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1. In File Explorer, right-click the PDF and select Properties.
2. Look at Size on the General tab.

Why it matters: Gmail, for example, limits attachments to 25 MB for personal accounts. If you attach something bigger, Gmail removes the attachment and adds a Google Drive link to it instead. For Google Workspace work and school accounts, the administrator sets the limit.

Expected result: you know the starting size, so you can see how much each method saves.

2. Save It Again at Minimum Size From Excel or PowerPoint

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If the PDF came from an Office file you still have, the quickest fix is to make it again at a smaller size. Microsoft recommends the minimum size option when file size matters more than print quality.

1. PowerPoint: select File > Export, then PDF (*.pdf) in the Save as type list.
2. Excel: select File > Save As or Save a Copy, then PDF in the Save as type list.
3. Choose Minimum size (publishing online) instead of Standard (publishing online and printing).
4. Save the file with a new name, so you keep the original.

Expected result: the new PDF is smaller than the one saved at Standard.

3. Compress the Pictures Before You Make the PDF

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Photos and scanned images can make a document large. Word, PowerPoint and Excel can shrink the pictures before you save as PDF.

1. Open the original document and select a picture.
2. On the Picture Format tab, select Compress Pictures in the Adjust group.
3. To compress every picture in the document, clear the Apply only to this picture check box.
4. Under Resolution, choose a lower resolution, then select OK.
5. Save the document as a PDF again: in Word, select File > Save a Copy > Browse and choose PDF.

Expected result: the new PDF is smaller. Zoom in on the pictures to make sure they still look clear enough.

4. Keep Only the Pages You Need

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If people only need part of a long document, a PDF with fewer pages is smaller. Windows includes a printer called Microsoft Print to PDF that saves what you print as a new PDF.

1. Open the PDF in Microsoft Edge.
2. Press Ctrl + P.
3. Choose Microsoft Print to PDF as the printer.
4. Under Pages, choose Custom and enter the pages you want, such as 1-5.
5. Select Print, then choose a name and folder for the new file.

Making the PDF in Word? Select Options in the save window and set a Page range instead.

Expected result: a new, shorter PDF with only the pages you chose. You can repeat this to split a big PDF into several smaller ones.

5. Zip the PDF

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Microsoft notes that zipped (compressed) files take up less storage space and can be transferred more quickly. Zipping also lets you send several PDFs as one file.

1. Right-click the PDF (or several selected PDFs).
2. Select Show more options > Send to > Compressed (zipped) folder. On Windows 10, Send to is in the first menu.
3. Send the new .zip file. The person you send it to can right-click it and select Extract All.

Expected result: a .zip file next to the original. Compare the sizes: how much you save depends on the PDF.

6. Share a Link Instead of Attaching the File

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If the file is still too big, don't attach it at all. Put it in your OneDrive folder and send a link.

1. Move or copy the PDF into your OneDrive folder in File Explorer.
2. Right-click it and select Share a OneDrive link. The link is copied for you.
3. Paste the link into your email or message.

Links made this way let people edit by default. To change that, share from OneDrive.com instead and turn off editing in the link settings.

Expected result: the recipient opens the PDF from the link, and nothing large is attached to your email.

7. Compress a PDF on a Mac With Preview

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1. Open the PDF in the Preview app.
2. Choose File > Export.
3. In the Quartz Filter pop-up menu, choose Reduce File Size.
4. Give the file a new name in Export As so you keep the original, then click Save.

Expected result: a smaller copy of the PDF. Apple notes it may be lower quality than the original, so check it before you send it.

Still Too Big? What to Try Next

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• Combine methods: compress the pictures, save at minimum size, then zip the result.
• Split it: use the page range steps in section 4 to make two or three smaller PDFs.
• Use a link: with a OneDrive link (section 6), nothing is attached to the email, so attachment limits don't apply.

Need to make a PDF from pictures first? See How to Convert PNG to PDF for Free, and for the basics, What Does PDF Stand For?