Which level should I choose?
- Lossless — rewrites the file structure: compressed object streams, maximum Deflate compression and removal of unused resources. Nothing visible changes. Helps most with PDFs exported from office software; scans rarely shrink much.
- Balanced (recommended) — also re-encodes embedded photos as JPEG at quality 75, capped at 2000 pixels on the long side. Text and vector graphics are untouched and stay sharp and selectable. This is where most size is saved on photo-heavy documents and scans.
- Strong — photos are capped at 1400 pixels at quality 60, and uncompressed-looking images (screenshots, some scans) are converted to JPEG too. Visibly softer photos, much smaller files.
- Pages as images — renders every page as a JPEG image. Often the smallest option for scans and complex layouts, but text is no longer selectable or searchable and vector graphics become pixels. Use it only when you just need something small enough to send.
Honest results
You always see the exact size before and after. If a level can't make a file smaller — for example a PDF that's already well compressed, or one that's mostly text — you get the original back and are told so, rather than a "compressed" file that is actually bigger. Try a stronger level if you need more.
Check the result before sending it, especially for scans with small print: zoom in on a page or two. For email the usual limit is 10–25 MB; many upload forms allow 2–5 MB.
Password-protected files work too: you're asked for the password, the file is unlocked in your browser, and the result is saved without a password. Files that only restrict printing or copying are opened automatically.
Are my files uploaded?
No. Compression runs with JavaScript and WebAssembly running in your browser tab. Your files are read from your device and the results are created on your device; nothing is sent to gratistools.be or anyone else, which is also why there are no queues, daily limits or watermarks. See the privacy page.