You don't need special software to shrink a PDF's file size on Android. FernPDF runs entirely in Chrome on Android: 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%.
Works with files from Google Drive, Downloads or local storage. Because nothing uploads, it's quick even on mobile data, because you only pay bandwidth for the page itself.
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 Chrome on Android 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.