How to compress a PDF for email

Email and upload forms still cap PDF size. Gmail’s attachment limit is 25 MB. Outlook.com is typically 20 MB. Many government and university portals sit at 5–10 MB. A phone-scanned contract or a slide deck export blows past those numbers because each page is really a photograph.

Compressing re-encodes those page images so the file drops without opening Acrobat. Filvo does this in the tab: the PDF is not uploaded to our servers.

Why scans are huge

A 300 DPI camera page stored as a lightly compressed JPEG can be 2–4 MB by itself. Ten pages and you are already over a 25 MB inbox. Vector invoices and text-only exports are usually small already — compression will not invent savings there, and Filvo will show that the file is already optimal.

Balanced vs Strong

Drop one unlocked PDF (up to 40 MB) into Filvo and start on Balanced. Preview a page. If the file is still too heavy for the inbox or portal, switch to Strong. Camera scans shrink the most. Already-tiny files may not move.

• Gmail: 25 MB per attachment (larger files become a Drive link).
• Outlook / Microsoft 365: often 20 MB for consumer mail; work tenants can be lower.
• Portals: read the form — 5 MB and 10 MB caps are common.
• If Strong is still too big, split the PDF and send the pages you actually need.

The flattening tradeoff

Pages are flattened into images, so text is usually not selectable afterward. That is fine for a signed scan you only need to read. Keep the original if you still need copy-paste, form fields, or a digital signature. Flattening also means you should not compress a file you plan to OCR later.

The email compressor page starts on Strong so a typical scan has a better chance of clearing the inbox on the first try. After you shrink a file, you can still merge it with another PDF or convert pages to JPG.