How to compress a PDF
- Choose the PDF. Drop it onto the box or click to select it.
- Pick a level. Recommended is right for most files. Use Strong when a form has a tight limit, Light when you still want to print the document, and Lossless when the text must stay selectable.
- Compress and download. You see the old and new size and how much was saved. If the result is not smaller, keep your original.
What the levels do
- Lossless rewrites the file more efficiently (compressed object streams, unused data removed). Text, links and vector graphics stay exactly as they were. Savings are usually small, from 0 to about 20 %.
- Light, Recommended and Strong redraw every page as an image at 150, 110 or 75 dpi and store it as a JPEG. This is what makes scanned documents and photo-heavy PDFs dramatically smaller, often by 60–90 %. The downside: text in the new file is part of the picture, so it cannot be selected, searched or copied.
- Grayscale removes colour as well, which helps further with coloured scans of black-and-white letters.
Which level should I use?
For scans from a phone or office scanner, choose Recommended: 110 dpi is still easy to read on screen and in a normal printout. For an online application with a 1 or 2 MB limit, try Strong and check the result. For PDFs created directly from Word or another program, the file is mostly text that is already small, so try Lossless first; rasterizing such a file can even make it larger.
Example
A 6-page scanned rental contract of 14.8 MB, compressed with Recommended, typically ends up around 1.2–1.8 MB, a saving of roughly 90 %. With Strong and grayscale it may drop below 600 KB, which fits almost any upload form. A 40-page text report exported from Word (900 KB) would shrink only slightly with Lossless, and that is expected.
Privacy
Online compressors usually upload your PDF to a server. Here the document is opened with Mozilla's pdf.js and rebuilt with pdf-lib inside your browser, so contracts, payslips and medical documents never leave your device. Nothing is stored.
Need only part of the document? Split the PDF first. To shrink photos before putting them into a PDF, use the image compressor.
Frequently asked questions
Is this PDF compressor free?
Yes. It is free, with no sign-up, no watermark and no limit on files or pages. The compression runs in your browser.
Is my PDF uploaded to a server?
No. The PDF is compressed on your own device and never uploaded or stored.
How much smaller will my PDF get?
Scanned and photo-heavy PDFs usually shrink by 60 to 90 percent with the Recommended or Strong level. PDFs that are mostly text are already small and shrink much less.
Will the text still be selectable?
With Lossless, yes. The other levels turn each page into an image, so the text can be read but not selected or searched.
Why is my compressed PDF not smaller?
The file is probably already well compressed, or it is mainly text and vector graphics. Try another level, or keep the original.
Can I compress a password-protected PDF?
No. Encrypted PDFs have to be unlocked first in a PDF reader that knows the password.