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How to compress a PDF on Windows

Windows can open a PDF in Edge and print to PDF, and that's about the extent of it. Anything structural means installing software — and most free Windows PDF editors bundle extras you don't want or watermark the output. Running the job in the browser you already have open avoids installers, admin rights and watermarks entirely.

Hitting an attachment or upload limit is the most common reason people go looking for a PDF tool at all — the portal rejects a 12 MB file and you need it under 5 MB right now.

Open Compress PDF →

Step by step on Windows

  1. 1Open the Compress PDF tool and upload your PDF.
  2. 2Choose a level: Light keeps text selectable, Balanced suits most documents, Strong makes scans as small as possible.
  3. 3Click “Compress PDF” and download the smaller file — you'll see the before and after sizes.

Click to browse and use the standard Windows file dialog, or drag the PDF from File Explorer or your desktop directly onto the page.

Where the finished file is saved on Windows

Edge and Chrome save to your Downloads folder and show the file in the downloads flyout at the top-right. Open File Explorer → Downloads to find it later, or drag it from the flyout straight into an email.

What Windows can’t do on its own

Windows has no built-in PDF editor. Edge can view and annotate, and 'Microsoft Print to PDF' can create one — but merging, splitting, page editing and OCR all require third-party software, which on a managed or work PC you may not even be allowed to install.

FAQ

Do I need admin rights or an installer for this?
No. Nothing is installed, so it works on locked-down work and school PCs where you can't install software.
Will the finished PDF have a watermark?
No. Many free Windows PDF utilities stamp their logo on the output unless you pay — this doesn't add anything to your document.
How much smaller will my PDF get?
It depends entirely on what's inside. Scanned documents and photo-heavy files often shrink by 70–90%. A PDF that's mostly text may only shrink a little, because there wasn't much to remove in the first place — we'll show you the real before and after numbers rather than a vague promise.
Will compressing ruin the quality?
Light is lossless — nothing is degraded at all. Balanced re-encodes pages as images at a quality that still looks clean on screen and in normal printing. Strong prioritises the smallest possible file, so fine detail softens; it's meant for scans you need to read rather than reproduce.
Why is my text no longer selectable after compressing?
Balanced and Strong work by turning each page into an image, which is what makes big files shrink dramatically — but images have no text layer. If you need to search or copy text afterwards, use the Light level, which keeps the document's text intact.
My file didn't get smaller — why?
Some PDFs are already fully optimised, and squeezing them further would actually make them bigger. When that happens we hand back your original file untouched instead of a larger “compressed” version. Trying a stronger level usually helps.
Is there a file size limit?
No fixed limit. Compression runs on your own device, so the practical ceiling is your browser's memory — everyday documents up to around 100 MB work comfortably.
Is pdfcdf free to use?
Yes. Every tool on pdfcdf is completely free, with no account, no watermarks, and no limits on how many files you process.
Are my files safe? Do they get uploaded?
Your files never leave your device. Every tool runs entirely in your browser, so your documents are processed locally and are never uploaded to a server or seen by anyone.
Do I need to create an account or sign up?
No. pdfcdf works instantly with no sign-up, no email, and no software to install — just open the tool and go.
Does it work on mobile phones and tablets?
Yes. pdfcdf runs in any modern browser on phones, tablets, Mac, Windows and Linux — nothing to download.

Ready to compress a PDF on your Windows?

Open Compress PDF →

Same tool, other devices

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