A 100MB PDF won't email anywhere. Most chat apps choke. You need a working delivery method.
What's actually going wrong
100MB exceeds every consumer email cap. Most chat apps allow it in theory but struggle in practice. Even cloud sync can be slow at this size.
The routes that work: compress aggressively, split, or share via cloud link.
The quick fix
Compress PDF first. A 100MB scan typically comes down to 8-15MB — emailable. Compressed first, then attach normally.
For files that stay large after compression, share via cloud link (Drive, OneDrive, Dropbox, WeTransfer). Upload once, send the link.
If that didn't work
If compression doesn't shrink the file enough, split it into smaller PDFs. Three 33MB parts beat one 100MB file. Recipients merge if needed.
For PDFs with content that can't be compressed (high-resolution graphics necessary for purpose), cloud sharing is the right route. Don't try to force them through email.
Prevent it next time
Question what makes a PDF 100MB. Scanner colour mode? Uncompressed images? Unnecessary high resolution? Often the source is fixable at creation time.
FAQ
Can compression handle 100MB PDFs?
Usually substantially. Scanned 100MB PDFs typically come down to 10-15MB. Image-heavy PDFs lose 60-80%. Already-optimised PDFs lose less.
What's the best cloud service for sharing large PDFs?
WeTransfer for one-off (no account needed). Google Drive or Dropbox for ongoing. SharePoint for corporate. All handle 100MB easily.
Will recipients accept WeTransfer links?
Generally yes — widely recognised, no account required to download. Corporate spam filters sometimes flag them; check before relying.
Can I email a 100MB PDF on any service?
ProtonMail Plus and some enterprise providers allow large attachments, but recipient servers often reject. Compression or cloud sharing is more reliable.
100MB needs strategy. Compress in Flint first, then choose delivery.