How to compress a PDF
- 1 Drop your PDF into the box, or press browse to pick it.
- 2 Choose a level: Light for sharp text, Recommended for most files, or Strong for the smallest size.
- 3 Press Compress PDF. The smaller file downloads automatically.
- 4 Check the before and after sizes. If it is still too big, try a stronger level.
Why some PDFs are large, and what actually shrinks them
Almost all of a PDF's size comes from images: scanned pages, photos and screenshots. Text and fonts are tiny by comparison. A 10-page Word export is often under 200 KB, while 10 phone-scanned pages can easily be 15 MB.
- Scans and photo-heavy PDFs shrink the most, often by 70% to 95%, because images can be resized and re-encoded.
- Text-only PDFs are already small; rebuilding the file usually saves 5% to 30%.
- Black and white helps scanned documents a lot, because greyscale images need far fewer bytes.
This tool shrinks only the images inside the file, so text stays sharp and selectable. If a form asks for an exact limit, use Compress PDF to 100KB, 200KB or 500KB, which aim for the target size automatically.
Features
Three compression levels
Pick the balance between quality and size that suits the file.
Text stays sharp
Only the photos and scans inside the PDF are made smaller. Text, fonts and lines are left untouched, so they stay crisp.
Before and after
See the exact saving in KB or MB and as a percentage.
Private by design
Your PDF is processed on your device and never uploaded.
When to use it
Email attachments
Get a large scan under the 20 or 25 MB attachment limit. Saving a page as an image instead? PDF to PNG keeps it sharp. Big photos? Turn them into a PDF with JPG to PDF, then compress it here.
Job and visa portals
Many upload forms only accept PDFs under 1 or 2 MB. For attachments with a fixed limit, Compress PDF to 500KB does the guessing for you.
Phone storage
Shrink manuals and e-books you keep on your phone. If the form also wants a photo, Compress Image to 100KB handles JPG files.
Messaging apps
Send documents faster on slow mobile data. Check how many pages you are sending with the PDF Page Counter.
Related PDF tasks
Frequently asked questions
Is my PDF uploaded to a server?
No. The file is opened and processed by your own browser. Nothing is sent to us or anyone else, so it is safe for bank statements, contracts and ID documents. Once the page has loaded, the tool even works offline.
How much smaller will my PDF get?
It depends on what is inside. Scanned documents and PDFs full of photos often shrink by 50% to 90%. Text-only PDFs are usually already small and may only shrink a little.
Will the quality drop?
Light compression keeps pages very close to the original. Strong compression makes photos and scans softer, so check the result before you send it.
Can I still select the text after compressing?
Yes, in almost all cases. The tool shrinks the images inside the PDF and leaves the text as real text. Only with Strong, and only when it makes the file much smaller, are pages saved as pictures, and the tool tells you when that happens.
What does Black and white do?
It turns images into greyscale, which makes scans and photos of documents much smaller. At the same file size, that leaves room for more detail, so text in scans looks sharper.
Can I check the quality before sending?
Yes. After compressing, a zoomed-in before and after view of page 1 appears, so you can see the result straight away.
Why didn't my PDF get smaller?
Some PDFs are already well compressed. If neither method saves at least a few percent, the tool tells you instead of giving you a bigger file.
Is there a file size limit?
There is no fixed limit, but very large PDFs with hundreds of pages need more memory. On a phone, files up to about 100 MB usually work well.
Does it work with password-protected PDFs?
No. Remove the password first, then compress the file.
Is it free?
Yes. There is no sign-up, no watermark and no daily limit.
How this tool works. These PDF tools run entirely in your browser using two widely used open-source libraries: PDF.js, the PDF engine built into Firefox, to read and render pages, and pdf-lib to create and edit files. Each tool is tested with typed documents, phone scans and photo-heavy files before it goes live, and nothing you open is sent to a server.
Built and reviewed by Hamza Farooq, founder and lead developer
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