How to Compress Images for Email
Email was not built for 12MB photos. Gmail caps messages at 25MB, Outlook at 20MB — and a handful of phone photos will sail right past both, bouncing your message back. The fix is not sending fewer photos; it is sending smarter photos. Shrinking each image to email-friendly dimensions and sensible quality turns a 60MB attachment disaster into a tidy 4MB message. Re-Sizefy batch-processes the whole set in your browser, so private family photos never touch a server.
Step-by-step: make photos email-ready
- Drop in all the photos. Drag the entire batch into the drop zone — this is exactly what batch mode is for.
- Resize the long edge to 1600px. Nobody views email photos larger than that, and it is the single biggest size reduction you can make.
- Choose JPG at quality 75. JPG is the safest format for email — every client on earth displays it inline. Quality 75 looks great at email sizes and keeps each photo to a few hundred kilobytes.
- Check the total. Twenty photos at ~300KB each is ~6MB — comfortably under Gmail's 25MB and Outlook's 20MB limits, with room to spare.
- Download the ZIP, attach, send. One ZIP with all the compressed photos, or download individually — then attach as normal.
Quality tips
Stick with JPG for email, not WebP. WebP support in email clients is good but not universal — some recipients would see a download prompt instead of the photo. JPG always just works.
If you are sending to someone who will print the photos, send two sets: compressed JPGs in the email body for viewing, and a cloud link to the full-resolution originals.
Use the file renaming options to number the batch (001, 002…) so photos arrive in the order you intended.
Things to watch out for
- Watch the 25MB / 20MB ceilings. Gmail allows 25MB total per message, Outlook 20MB — and that includes message overhead. Aim to stay under 15MB of attachments to be safe everywhere.
- Do not compress an already-compressed set twice. If you already shrank these photos last month, re-shrinking them again just adds artifacts. Work from the originals.
- HEIC from iPhones. If your iPhone sends HEIC files that the recipient cannot open, convert to JPG first — JPG is the lingua franca of email attachments.
Try it now
Open the free Re-Sizefy converter — drop in your photos, set 1600px and JPG 75, and email without bounce-backs. No sign-up, no upload.
Frequently asked questions
What is the email attachment size limit?
Gmail allows 25MB per message, Outlook 20MB. Staying under ~15MB of attachments works reliably across all providers.
What size should photos be for email?
1600px on the long edge at JPG quality 75 — sharp on any screen, roughly 200–400KB each, so dozens fit in one message.
Should I use JPG or WebP for email?
JPG. Every email client displays JPG inline; WebP support is widespread but not universal, and some recipients would only get a download link.
Are my family photos uploaded anywhere?
No. Compression happens locally in your browser — nothing is sent to any server, which is exactly what you want for personal photos.