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%.
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 tool.
2Drop your PDF, and you'll see the original size immediately.
3Pick a level: Less, Recommended, or Strong, and preview the estimated savings.
4Click “Compress PDF” and download the smaller file.
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 using WebAssembly.
Yes. Every core FernPDF tool is free, with no account, no watermark, and no trial limits.
It depends on the content. Image-heavy PDFs often shrink 60–90%; text-only files less. The estimate updates live as you pick a level, and you only download if you’re happy with the result.
“Recommended” is visually lossless for most documents. “Strong” downsamples images more aggressively for the smallest size. You preview the trade-off before downloading.