Compress PDF to Fit Email Attachment Limits

Email providers cap attachment sizes — Gmail at 25MB, Outlook at 20MB, Yahoo at 25MB — and corporate mail gateways are often stricter. If your PDF bounces or your mail app silently turns it into a download link instead of an attachment, compressing it first is the reliable fix.

Why use this page?

  • Sized for real provider limits: Gmail 25MB, Outlook 20MB, Yahoo 25MB
  • Avoids your attachment being replaced by a cloud download link
  • Formatting, fonts, and signatures stay intact
  • Compress several attachments in one batch before composing your email
  • Nothing to install — works in the browser on phone or desktop

How it works

  1. Upload the PDF you want to send.
  2. Choose 'Recommended' compression first — it keeps the best visual quality.
  3. Check the new file size against your email provider's limit (see the FAQ below).
  4. If it's still too large, run it again with 'Maximum' compression.
  5. Download and attach the smaller file to your email.

Frequently asked questions

What is Gmail's attachment size limit?

Gmail accepts attachments up to 25MB. Above that, it automatically uploads the file to Google Drive and sends a link instead — which some recipients can't or won't open. Compressing below 25MB keeps it a real attachment.

What about Outlook and other providers?

Outlook.com and many Microsoft 365 setups cap attachments around 20MB, Yahoo allows 25MB, and corporate mail servers are often configured even lower. When in doubt, aim for under 10MB — it sends faster and lands more reliably everywhere.

Why not just zip the PDF instead?

ZIP barely shrinks PDFs — usually less than 10% — because PDF content is already compressed internally. A real PDF compressor rebuilds the file and downsamples embedded images, which is where the actual size lives.

Will the recipient notice any difference?

Text, tables, and signatures remain identical. On 'Recommended' compression even photos in the document look the same on screen. Only 'Maximum' mode visibly softens large images.

Should I compress or split the PDF across two emails?

Compress first — one complete document is easier for the recipient than parts. If the file is enormous (a 200-page scan, for example), split it into logical sections and send them as a short series with clear file names.