How to fit photos and PDFs under an email attachment limit
Email was designed for text. Attachments still have limits, and they are smaller than they look, because of how email carries files.
Published limits
| Service | Published limit | When it is exceeded |
|---|---|---|
| Gmail (personal accounts) | 25 MB | Gmail removes the attachment and adds it as a Google Drive link. |
| Outlook.com | 20 MB, including the message | Microsoft suggests sharing a OneDrive link instead. |
| Work and school accounts | Set by the administrator | Ask your IT team. |
The receiving side matters too. A colleague’s company server may accept less than your provider sends.
Why files grow in transit
Attachments are converted to plain text for the journey using Base64, which turns every 3 bytes into 4 characters. That makes the attachment about a third larger. A 20 MB file becomes roughly 27 MB inside the email, which can push it over a 25 MB limit. To be safe, aim for attachments well under three quarters of the limit.
Shrinking photos
- Resize first. A phone photo is often 4000 pixels wide; 1600 to 2000 pixels is plenty for viewing on a screen. Use the image resizer and keep the proportions.
- Compress with the image compressor. It shows the size before and after, so you can stop as soon as the file is small enough.
- Send several photos? Compress each one, then add up the sizes before attaching.
Shrinking PDFs
- Send only the pages needed with Extract PDF pages.
- Split a long document into parts with Split PDF and send it over several emails.
- For scans, rebuild the PDF from smaller images. The PDF size guide walks through it.
A quick check before you press Send
- Add up the attachment sizes shown by your file manager, then add about a third for encoding.
- If the total is close to the limit, shrink the largest file first; one big photo or scan is usually most of the size.
- Open each shrunk file once to make sure it is still readable, especially text in scans and receipts.
- Sending to a work or school address? Its mail server may accept less than personal email services, so leave extra room or share a link instead.
When to send a link instead
Videos, large sets of photos and anything over the limit after a reasonable reduction are better shared as a link from a cloud storage service. Links also let the recipient download the file whenever they are ready, and they do not fill up mailboxes.
Tools for this guide
Sources
Written with AI assistance, then checked against how HandyTechHelper’s tools actually behave. Figures from other companies link to their source. Spotted a mistake? Tell us.