How Compress works
Compress runs entirely in your browser. Your files are never uploaded, so we can't see them, keep them or lose them.
What happens to your file
- 01You pick a file. This page reads it on your device.
- 02It's compressed in the background, still on your device. Photos are resized and re-saved. Text in PDFs stays sharp and selectable.
- 03You download the smaller copy. Closing the tab clears everything.
Limits
Because everything runs on your device, how big a file we can handle depends on your device.
| Device | Works well | May be slow or stop |
|---|---|---|
| Phone | Up to 200 MB | Over 200 MB |
| Computer | Up to 1 GB | Over 1 GB |
These are guides, not hard limits. If a file is too big, you'll see a clear message. Nothing is lost, and nothing is uploaded.
What won't shrink much
- PDFs that are mostly text. There are no photos to make smaller.
- Files that are already compressed. We keep the original rather than give you a bigger file.
- Password-protected PDFs can't be opened. Remove the password first.
Privacy
- No uploads. Your files stay on your device.
- No accounts, no tracking, no ads.
- Photos lose hidden details like location and camera.
- Works offline once the page has loaded.
- Open source, so anyone can check. Read the code