Gmail and Outlook.com cap attachments at about 20–25 MB per message, and many company servers are stricter. Attachments also grow by about a third when encoded for sending, so a 20 MB set can still bounce. A handful of phone photos is enough to hit the limit.
This page sets JPEG output, a 1920-pixel width and a 500 KB target. Each photo still fills a laptop screen, and a batch of 20 comes to about 10 MB.
How to compress photos for email
Drop all the photos
Mixed formats are fine. They will all come out as JPEG, which every email client opens.
Download the ZIP or single files
Attach the files, or the ZIP if your recipient prefers one attachment.
Check the total
Add up the sizes on the result cards. Stay under about 15 MB to be safe with strict servers.
Why compress before attaching
No bounce messages
Messages over the recipient server’s limit are rejected, sometimes hours later. Smaller attachments avoid that.
Faster on mobile
Recipients on a phone do not have to download 50 MB to see a few pictures.
Why your mail app’s “reduce size” is not always enough
Phone mail apps offer small, medium and large options, but the sizes are fixed and quality is not shown. Doing it here lets you see the result before sending and keeps the same settings for every photo.
For many full-resolution files, a shared folder link is better than an attachment. For a few viewable photos, compressed attachments are simpler for the recipient.
How many photos fit
| Mail limit | Photos at 500 KB |
|---|---|
| 10 MB | About 14 |
| 20 MB | About 28 |
| 25 MB | About 35 |
Email image questions
What size should images be for email?
About 1920 pixels wide and 300–500 KB each as JPEG. That looks good on any screen and fits many photos in one message.
Why did my email bounce with fewer than 25 MB?
Attachments grow by about a third when encoded for email, and some servers set lower limits than Gmail.
Should I send WebP or HEIC by email?
No. Some recipients cannot open them. JPEG is the safe choice, which is why this page outputs JPEG.
Are the photos uploaded to compress them?
No. They are compressed in your browser, then you attach them yourself.