WhatsApp allows large documents, but sending a 40 MB scan over mobile data is slow for you and storage-hungry for everyone in the group. Compressing first makes the send near-instant and is kinder to phones.
Because FernPDF runs in the browser, this works directly on your phone: open the tool in Chrome or Safari, compress, then share the downloaded file to WhatsApp.
Step by step
1On your phone or computer, open the Compress PDF tool.
2Drop or select the PDF.
3Pick “Recommended” (or “Strong” for scans).
4Download, then attach it in WhatsApp as a document.
No upload · no account · no watermark
FAQ
Common questions
Yes, it runs in Safari on iPhone and Chrome on Android. No app needed.
Faster sending on mobile data, less storage used on every recipient's phone, and group chats stay light.
It never leaves your device during compression. Only WhatsApp itself transmits the file you choose to send.