Compress a PDF
Make a PDF smaller for email or upload limits. You see the new size before you download, and if it isn’t smaller you keep your original.
- 1Add your file
- 2Make it yours
- 3Download & done
Let’s start with your file.
Drop your PDF here. We’ll take it from there.
PDF documents·Or drag and drop a file
Choose a different fileYour files stay on this device. Always.
How to compress a PDF
- Choose a PDF.
- Pick Lossless (keeps everything) or Strong (best for scans and photo-heavy files).
- Compare the sizes and download the smaller file.
Good to know
Lossless rewrites the file’s internal structure with the open-source qpdf engine. It packs objects together and recompresses data streams. Nothing visible changes, and text stays selectable. Gains are modest: often 5–30% on files exported by office software, less on files that are already tight.
Strong redraws each page as a JPEG image at the resolution you choose. Scans and photo-heavy PDFs often shrink by half or more. The trade-off is that text becomes part of the picture, so you can no longer select or search it. Use it for scans, not for text documents you still need to copy from.
Online services that promise a 90% reduction on every file are usually doing the strong kind of compression without saying so.
Questions
Is my file uploaded anywhere?
No. PDF1 runs the whole job inside your browser tab with JavaScript and WebAssembly. The page has no upload endpoint, and its security policy blocks connections to other servers, so the file stays on your device. You can even disconnect from the internet once the page has loaded.
Why did my file barely shrink?
Text-only PDFs exported from Word or a browser are already compact. There is little to remove without damaging them. Lossless gains are largest on older or unoptimised files, and strong mode helps most on scans.
Which resolution should I pick in strong mode?
150 dpi is a good default for reading on screen and printing at home. Pick 100 dpi for the smallest files, or 200 dpi if small print must stay crisp.
Will links and form fields survive?
Lossless keeps them. Strong mode turns each page into an image, so links, form fields and selectable text are lost.