Why does Preview's "Reduce File Size" look so bad?

Its filter forces all images to one crude resolution regardless of content. Proper compression adapts per image — the difference is dramatic on scans.

Do I need to install anything on my Mac?

No — the browser does everything; processing runs server-side.

Can I hit an exact size like 100KB on Mac?

Yes — enter the KB target; that precision is exactly what Preview cannot offer.

Compress PDF on Mac

Macs ship with Preview\'s "Reduce File Size" filter — famous for crushing documents to illegibility with no middle setting. The browser route gives you quality control and exact KB targets instead, no installs. We compress toward your target at the best quality that fits, never make the file larger than the original, and always show the real final size — very image-heavy files may land slightly above tight targets.

Free Encrypted Deleted in 1 hour

1Upload
2Configure
3Download

Drag & drop your file here

or click to browse · Up to 15 MB

Select file

Accepted: PDF

256-bit SSL encrypted No sign-up to start Auto-deleted in 1 hour

Your files are processed temporarily and deleted automatically — there is no general cloud storage. File deletion.

How to compress pdf

Simple steps — no software to install.

1
Open Compress PDF in your browser
Safari, Chrome, Firefox — any.
2
Upload and set a target if needed
Exact KB aiming Preview cannot do.
3
Download
Straight to your Downloads folder.

Why use our Compress PDF

Secure & private

Files are encrypted in transit and deleted automatically after processing.

Fast results

Optimized processing returns your file in seconds.

Free to start

Core tools are free with daily limits — no install required.

Works anywhere

Runs in your browser on any device, anywhere in the world.

The Preview problem

Preview's built-in Quartz filter is all-or-nothing: it hammers every image to the same low resolution, turning readable scans into smudges. Fine for rough drafts; wrong for anything submitted. Browser-based compression balances quality against size properly.

Works on every Mac, nothing added

Safari, Chrome or Firefox — upload, compress (with an optional KB target), download. Apple Silicon or Intel, macOS old or new: the processing happens server-side, so the Mac just needs a browser.

Quality control Preview lacks
Exact KB targets
No apps or extensions
Any macOS, any browser
Free with fair daily limits