Compress a PDF online, losslessly or as small as possible
Shrink a PDF that is too heavy for an email, a government portal or a job application. Two levels to choose from: a lossless clean-up, or a strong compression that turns pages into images while keeping the text selectable. Everything happens in your browser: the file never leaves your device, with no account and no limits.
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The same PDF reader, installed on your computer: it opens your files offline, with no account, and can become your default PDF reader.
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Windows (offline installer, x64) · Windows (offline installer, ARM64) · Windows (MSI for managed fleets)
Drop your PDF here
or choose a file on your computer, tablet or phone
Word, Excel, PowerPoint, text, RTF, images and HEIC photos are converted to PDF on your device.
100% local reading: the document is never sent over the internet.
How to reduce the size of a PDF in three steps
- 1
Open the PDF to shrink
Drag the file into the reader or pick it from your device, then open the Compress tool: its current size is shown.
- 2
Choose the compression level
Lossless: the file is cleaned up and rewritten without touching the content. Strong: every page becomes a 110 dpi image, with the text still selectable, to get under a form's size limit.
- 3
Download the compressed PDF
The new size appears once compression is done: review the result in the reader, then save it or send it for signature.
Everything happens in your browser: the file never leaves your device. Open in the reader
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Compressing PDFs: frequently asked questions
How much smaller will the PDF be?
It depends on the content and the level you choose. Strong compression shrinks PDFs made of scans or photos considerably; lossless compression often saves a few percent, sometimes a lot on a poorly optimised file. A text-only document is already compact.
Does compression degrade quality?
Not with lossless compression: the file is only cleaned up. With strong compression, every page becomes a 110 dpi image: very readable on screen, less sharp when printed or zoomed in, and vector drawings turn into pixels. The text stays selectable and searchable.
Is my PDF uploaded to be compressed?
No. Compression is computed by your browser, on your device. Certyneo never receives the file, so you can shrink an ID document or a contract in complete privacy.
Can an electronically signed PDF be compressed?
Technically yes, but compression rewrites the file and invalidates any existing electronic signature. Compress the document before having it signed, never after.
What is the maximum size for a PDF sent by email?
Most mail services accept 20 to 25 MB per message, attachments included. Aim for under 10 MB to be sure the PDF gets through everywhere, including government portals.
Does this PDF need to be signed?
Send it for electronic signature in minutes: your signers sign from their phone, without creating an account.
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