How to reduce a PDF's file size on a Mac
Every Mac can compress a PDF via Preview's Quartz filter — and every Mac user who has tried it knows the result is often a grey, blurry mess. The filter is one fixed, aggressive setting with no middle ground. Here is a more controllable approach.
Drag and drop here, or choose from your device.
Up to 50 MB per file. Files are processed in your browser.
Full options and FAQs on the Compress PDF page.
Why Preview's filter disappoints
The built-in Reduce File Size filter re-encodes every image at a single low quality. On a text-heavy scan that can mean a huge saving; on anything with photos or colour it often produces visible smearing — and occasionally a bigger file than you started with. There is no slider, no preview and no undo beyond closing without saving.
Compressing in Safari instead
Add your PDF to the tool below and choose a level. Light keeps print quality, medium suits screen reading, and strong is for when only the words matter. You see the resulting size before you download, so you can step down gradually instead of gambling on one fixed filter.
Everything runs on your Mac — the file is never uploaded — which also makes it fine for confidential documents.
When the file is still too big
- Extract just the pages the recipient needs instead of sending the whole document.
- Split a long report and send it in two emails.
- Check the result was actually smaller — already-optimised files sometimes are not.
Step by step
- 1Open this page in Safari (or any browser) on your Mac.
- 2Add the PDF from Finder to the compressor below.
- 3Start at medium; step up or down based on the reported size.
- 4Download the result and compare it against the original at 100% zoom.
- 5Keep the version that is small enough and still sharp.
Frequently asked questions
- Is this better than Preview's Quartz filter?
- It gives you levels and a size readout instead of one fixed setting, so you keep more quality when you do not need maximum compression.
- Does it work on older Macs?
- Yes — anything running a current Safari, Chrome or Firefox. Processing happens on your machine, so older hardware simply takes a little longer.