Is it free to shrink a PDF's file size on Windows?

Yes. Every core FernPDF tool is free, with no account, no watermark, and no trial limits.

Does compression lose quality?

Recommended is visually lossless for most documents. Strong downsamples images harder, which shows on photographs and much less on scanned text.

Compress PDF Online Free: Reduce PDF File Size

Compress PDF Online Free: Reduce PDF File Size · Windows

How to shrink a PDF's file size on Windows

You don't need special software to shrink a PDF's file size on Windows. FernPDF runs entirely in Edge or Chrome on Windows: open the tool, drop your file, download the result. Compression re-encodes the document on your device. Image-heavy and scanned PDFs shrink the most, often 60–90%.

On Windows, you drag it into the drop zone from File Explorer, or click to open the native file picker. Once the smaller file is ready, it downloads to your Downloads folder in File Explorer, or wherever Edge or Chrome is set to save files, check the browser's download tray (Ctrl+J).

A locked-down work laptop that blocks .exe installers or needs admin rights for new software doesn't block a browser tab, so this works on managed corporate devices where installed PDF software often can't.

No desktop installer, no admin rights, no paid software. It works on locked-down work laptops because it's just a web page. Windows 10 and 11 are both fine.

Step by step

1Open the Compress PDF Online Free: Reduce PDF File Size tool in Edge or Chrome on Windows. No install, no account.
2Add your PDF: drag it into the drop zone from File Explorer, or click to open the native file picker.
3Pick a level: Less, Recommended, or Strong, and preview the estimated savings.
4Click “Compress PDF” and download the smaller file. It lands in your Downloads folder in File Explorer, or wherever Edge or Chrome is set to save files, check the browser's download tray (Ctrl+J).

No upload · no account · no watermark

FAQ

Common questions

Yes, FernPDF is a web app, so it runs in Edge or Chrome on Windows with no installation. All processing happens on your device, in this browser tab.

It depends almost entirely on how much of the file is images. The size shown before you run it is a projection from the level you picked, roughly four-fifths of the original at Less, a bit over a third at Recommended, under a fifth at Strong, not a measurement of your particular document. The real figure appears after the run, and if it isn't good enough you can pick another level and go again without re-adding the file.

Every FernPDF tool processes files in your browser: read how the privacy model works, or verify it yourself in your network tab.