Guide · 3 min read
How to email a PDF that's too large
What to do when Gmail or Outlook won't let you attach a PDF: compress it, split it or share it with a link, step by step.
You've scanned a contract, an assignment or some invoices, you go to send it and your email says the file is too big. It's one of the most common PDF problems, and it can be fixed in a couple of minutes.
How big can an attachment be?
Gmail allows attachments of up to 25 MB per message. Outlook and most email services have similar limits, usually between 20 and 25 MB. On top of that, many companies set lower limits on their servers, so a PDF that leaves your inbox fine may not reach the recipient.
As a rule of thumb, try to keep PDFs under 10 MB if you're going to email them. That way they'll get through almost anywhere.
Why your PDF is so big
It's almost always the images. A text-only PDF takes up very little space, even with a hundred pages. A scanned document or one made from phone photos, however, stores each page as a high-resolution image, and that makes the size explode.
Option 1: compress the PDF
It's the quickest fix. Compressing saves the PDF's images at a resolution suitable for reading on screen or printing at home, which is much lower than a phone photo. For scanned documents, the size usually drops by 50% to 90%.
- Open the Compress PDF tool and choose your file.
- Keep the “Recommended” level: it's the best balance between quality and size.
- Click “Compress PDF”, check the final size and download it.
- Open it before sending to make sure it's easy to read.
Tip: The stronger levels turn pages into images, so the text can no longer be selected. If the recipient needs to copy text from the document, use the “Basic” level.
Option 2: split it into several files
If it's still too big after compressing, or you don't want to lose quality, you can split it and send it in several emails. For example, a 60-page report as three files of 20 pages.
Option 3: share a link
For very large files, the easiest option is to upload them to a storage service such as Google Drive, OneDrive or Dropbox and send the link. Gmail and Outlook suggest this automatically when an attachment is over their limit. Keep in mind that in this case the file is stored on that service's servers.
Summary
- Up to 10 MB: send it as is.
- Between 10 and 25 MB: compress it to make sure it arrives.
- Over 25 MB: compress it; if that's not enough, split it or share a link.