PDF files are a go-to format for sharing documents thanks to their universal compatibility. However, they often balloon in size with multiple pages or embedded graphics, complicating emails and uploads.
Based on hands-on testing, we've curated the best free PDF compression tools—both online services and desktop apps—to help you shrink files effortlessly while maintaining quality.
Have a favorite free PDF compressor? Share it in the comments below.
Platform: Online
For a fast, no-download solution, Smallpdf excels with its intuitive drag-and-drop interface and quick processing. Accessible from any device and browser, it's perfect for on-the-go use.
Bonus features include direct imports from Google Drive or Dropbox, with options to save back to the cloud. The main limitation is two free compressions per hour (upgrade for $6/month unlocks more).
In my tests, it reliably reduced files to 144 DPI. A 5.72 MB PDF dropped to 3.17 MB, and a 96.98 MB file shrank to 87.12 MB—ideal for general size reduction without custom targets.
Platform: Online
iLovePDF offers precise control with three compression levels: low, recommended, and extreme. Upload from your device, Google Drive, or Dropbox for flexible workflows.
Processing is swift with no usage limits (one file at a time). Files auto-delete after about an hour, but easy downloads mitigate this. In tests, extreme mode halved a 97 MB file to 50.29 MB.
For superior online compression with customization, iLovePDF is a top choice.
Platform: Windows
This no-frills app works reliably on Windows 10 and earlier, despite infrequent updates. It's a solid offline option if web tools feel limited.
Choose from five presets, select input/output paths, and compress. The low-res preset slashed a 50 MB file to 15 MB effectively, though quality dips noticeably. It handles most files quickly, slowing only on massive ones.
Platform: Windows
PDF Compressor shines for batch processing multiple files at once. It runs smoothly on Windows 10, even without recent updates.
Compression varies—a 50 MB file lost just 1.5 MB—but speeds are excellent, and batch mode is free. Advanced settings require the paid version.
Beyond compression, delete unnecessary pages using tools like PDFSam to split, merge, and rearrange PDFs. Or zip files for extra savings. For more tips, see our guides on reducing PDF sizes with Windows tools or four ways to compress PDFs.
Do you frequently compress PDFs? What's your go-to free tool?
