Free PDF compressor
Compress PDF online
Shrink PDF files right in your browser. No upload, no signup, no limits. Documents never leave your computer.
Drop PDF files here or click to choose
PDF only. No upload, everything stays on your device.
Tip: works best on scanned documents and image-heavy PDFs. Pages are re-rendered as images, so text is no longer selectable in the output.
Drop one or more PDF files. Nothing is uploaded, so even huge documents open instantly.
Pick a quality level. 60 percent is a great balance of size and readability for most scans.
Hit Compress and download the smaller PDF. Batch as many files as you like.
Frequently asked questions
How does PDF compression work?
Each page is re-rendered and re-encoded at a lower image quality. Text stays readable while scans and photos shrink dramatically. Lower the quality slider for smaller files, or reduce scale to also lower the page resolution.
Are my PDFs uploaded to a server?
No. GIF Diet runs entirely in your browser. Files are processed on your own device and never leave it, which also makes compression start instantly with no upload wait.
Is it really free and unlimited?
Yes. There is no account, no watermark and no daily limit. Because processing happens on your device, we have no server costs to pass on to you.
Will my PDF still be selectable text?
This compressor rasterizes pages, which gives the biggest size reduction for scanned documents and image-heavy PDFs. Text becomes part of the page image, so use it when small size matters more than text selection.