The fastest way to shrink a PDF without paying
You can compress a PDF using free tools built into Windows and Mac, or through free online services that don't require installation. The method that works best depends on how much smaller you need the file to be and whether you want to keep the file on your computer or use a web browser.
Most PDFs compress to 50 to 80 percent of their original size without visible quality loss, especially if they contain scanned documents or photographs. If your PDF is mostly text, compression may do very little — text files are already small. If you need the file much smaller, you will have to accept lower image quality.
Key Takeaways
- Windows and Mac both have built-in compression tools that work on PDFs without installing anything new.
- Online PDF compressors like Smallpdf, ILovePDF, and PDF2Go work in your web browser and delete your file after compression.
- Compression usually reduces file size by 20 to 40 percent for typical PDFs, with minimal visible quality change.
- If you need much smaller files, you may have to choose between lower image quality or converting the PDF to a different format.
Compress a PDF on Windows using built-in tools
Windows does not have a dedicated PDF compressor, but you can use the Print to PDF feature to re-save the file at a smaller size. Open the PDF in any program that can read it — Microsoft Edge, Adobe Reader, or even Google Chrome. Press Ctrl + P to open the print dialog.
In the printer dropdown, select Print to PDF. Before you print, look for an Advanced or More settings option. Some print dialogs hide quality settings here. If you see an option for image quality or resolution, choose Low or Medium to reduce file size. Then click Print and save the new file with a different name so you keep the original.
This method works but is slow if you have many PDFs. For faster results, use an online compressor instead.
Compress a PDF on Mac using Preview
Mac's Preview app can compress PDFs directly. Open the PDF in Preview, then go to File and select Export. In the export window, make sure the format is set to PDF. Below the filename, you will see a Quartz Filter dropdown — click it and select Reduce File Size.
Click Save and choose a new filename so you keep the original. The compressed file will be noticeably smaller, though the quality loss is usually minor for documents with text and straightforward graphics. If the result is too blurry, repeat the process with the original file and skip the Quartz Filter step — sometimes the default export already compresses enough.
Use a free online PDF compressor
Online tools like Smallpdf, ILovePDF, and PDF2Go compress PDFs in your web browser without installing software. Go to the website, click the upload button, select your PDF, and the tool compresses it automatically. You then read the smaller file. Most of these services delete your file from their servers within a few hours.
The advantage of online tools is speed — you do not have to learn where settings are hidden in a print dialog. The disadvantage is that you are uploading your file to someone else's server. If your PDF contains sensitive information, use a local tool instead. Also, some free online compressors limit file size to 25 or 50 megabytes, so very large PDFs may not work.
Smallpdf and ILovePDF both offer a free tier that lets you compress two or three PDFs per day without creating an account. PDF2Go has no daily limit on the free version.
When compression does not work well
If your PDF is mostly text with few images, compression will shrink the file only slightly — maybe 5 to 10 percent. Text is already compact, and PDF compression targets images and graphics. If you need the file much smaller, you have two options: accept lower quality, or convert the PDF to a different format.
Converting to Word or another editable format can sometimes produce a smaller file, but you lose the original layout and formatting. If the PDF is a scanned document, converting to an image format like JPG will make it smaller but much harder to search or edit. For most situations, a 20 to 40 percent reduction in size is the realistic limit of free compression.
Comparing compression methods
| Method | Setup time | File size reduction | Best for |
|---|---|---|---|
| Windows Print to PDF | None | 20–40% | One or two PDFs, no new software |
| Mac Preview | None | 30–50% | Mac users, quick compression |
| Smallpdf or ILovePDF | None | 20–40% | Multiple PDFs, no installation |
| PDF2Go | None | 20–40% | Unlimited free compressions |
Frequently Asked Questions
Will compression make my PDF blurry?
Not usually. Most PDFs compress without visible quality loss because they already contain compressed images. If you use aggressive compression settings, photographs may look slightly softer, but text stays sharp. Test with one PDF first to see if the quality is acceptable.
Can I compress a PDF that is password-protected?
No. You must remove the password first using the program that created the PDF or a password-removal tool. Online compressors cannot read encrypted files.
How much smaller will my PDF get?
Most PDFs shrink to 60 to 80 percent of their original size. Text-heavy PDFs may shrink only 5 to 10 percent. PDFs with many photographs or graphics may shrink 40 to 50 percent. The only way to know is to compress one and check the file size.
Is it safe to upload my PDF to an online compressor?
Most reputable services delete files within hours and use encryption during upload. If your PDF contains confidential information, use a local tool like Mac Preview or Windows Print to PDF instead, which keeps the file on your computer.
What if the compressed file is still too large?
Try a more aggressive compression setting if your tool offers one, or convert the PDF to JPG images instead. You can also split the PDF into smaller sections and compress each one separately.