Email attachment limits are usually around 20–25 MB, and scanned PDFs blow past that fast. With PDF42 you can compress a PDF on your Android phone in a couple of taps.
Compress a PDF in 4 steps
- Open CompressIn PDF42, open Tools and tap Compress.
- Pick the PDFChoose the file you want to make smaller.
- Choose a levelPick a compression level to balance smaller size against visible quality.
- Save the smaller fileSave or share the compressed PDF — ready to email.
Most PDF compressors are websites or apps that upload your file to a cloud server, and many stamp a watermark on the result. PDF42 compresses on your device, so a confidential document never leaves your phone — and there's no watermark.
How much smaller will it get?
It depends on what's inside. Scanned or image-heavy PDFs usually shrink the most, since images are where the weight is. Text-only PDFs are already small, so expect a more modest reduction.
Will the quality drop?
Compression trades some image detail for a smaller file, so pick a lighter level if you need crisp scans, or a stronger one if you just need it under an email limit. Your original stays untouched — you save a separate compressed copy.