Compress PDF
Shrink a PDF's file size in your browser. Lossless mode for digital documents, raster modes for scans — with an honest before/after size report.
Choose a PDF
or drop files here
▚ files open locally — nothing is uploaded
- 01Choose or drop a PDF. It opens locally in your browser.
- 02Pick a mode: Lossless keeps everything intact; Balanced and Strong rebuild pages as images for big savings on scans.
- 03Click Compress. You'll see the exact before and after sizes, and the smaller file downloads to your device.
PDF compressors are where the upload problem bites hardest, because the files people need to shrink are usually scans — identity documents, signed agreements, medical records — being squeezed under an email attachment limit. ZorPDF compresses them without the round trip: the entire pipeline, including page rendering, runs in your browser.
We also tell you the truth about results. Compression is shown as real numbers — before, after, percentage saved — and if your PDF is already optimized and can't be made smaller, the tool says so instead of returning a padded file.
Which mode should I pick?+
Start with Lossless: it optimizes the file's internal structure without touching quality, and text stays selectable — typically 5–30% smaller. If your PDF is a scan (photographed or scanned pages), the raster modes save far more: Balanced keeps documents comfortably readable, Strong produces the smallest file for email attachment limits.
Why did the tool say there was nothing to save?+
Some PDFs are already well-optimized, and recompressing them would make the file bigger, not smaller. When that happens ZorPDF tells you honestly instead of handing you a worse file.
What's the catch with Balanced and Strong modes?+
They rebuild each page as an image, which is how they achieve large savings on scans. The trade-off: text in the output can't be selected or searched. For born-digital PDFs where text matters, use Lossless.
Is my PDF uploaded during compression?+
No. Compression — including the page rendering in raster modes — runs entirely inside your browser. The file never leaves your device.
Is there a size limit?+
No fixed limit. Very large scans take longer because your own device does the work, with a per-page progress bar so you can see it happening.