WhatsApp caps document sharing at 100 MB and re-compresses aggressively when it's forwarded, which can turn a scanned PDF into an unreadable blur.
Compressing the file in the browser first gives you control over the final quality: the recipient gets a smaller, sharper document, and WhatsApp doesn't need to touch it in transit.
How to use Compress PDF for WhatsApp
- Open Compress PDF and select the file you want to share.
- Let the tool re-encode the PDF and note the new file size.
- If it's still above 100 MB, split the PDF into chunks with Split PDF and send each part separately.
- Download the compressed file and share it in WhatsApp as a document (not as an image).
Tips that actually matter for this case
- Always send as a document — sharing a PDF as an image dumps it to WhatsApp's photo pipeline, which drops it to a tiny thumbnail.
- For scanned notes, target ~2 MB per 20 pages so the recipient can preview it on a slow mobile connection without waiting.
- If you're sharing an ID or invoice, run Protect PDF after compressing so a copy can't be re-shared without the password.