How to Compress Photos for Email Attachments

Why email attachments need compression

Modern phone cameras produce photos between 3 and 12 MB each. Attach five uncompressed iPhone photos to an email and you can easily exceed 30 MB — beyond the limit of Gmail, Outlook, and most corporate mail servers.

Even when photos fit within the size limit, large attachments cause other problems. They load slowly on mobile data, clog inboxes, and sometimes get rejected by the recipient's server. Compressing photos before sending is a simple courtesy that ensures your images arrive quickly and display correctly.

Email attachment size limits

These limits apply to the total size of all attachments combined. If you need to send more photos, compress aggressively, send multiple emails, or use a cloud sharing link.

Step-by-step: compress photos for email

1. Convert to a compatible format

If your photos are HEIC (iPhone default), convert them to JPG first. Most email clients and recipients cannot open HEIC files. Use the HEIC compressor to convert and reduce size in one step.

2. Compress JPG files

For photos already in JPG format, run them through a compressor:

1. Open the JPG compressor
2. Upload your photos (up to 30 at once)
3. Download the compressed versions

3. Resize if still too large

Compression reduces file size within the same dimensions. If photos are still too large, resize them to a reasonable viewing size. For email, 1920px wide is more than enough — most recipients view attachments on phone screens.

4. Check the total size

Before hitting send, verify the combined attachment size. On Mac, select all files and press Command+I. On Windows, right-click and check Properties. Stay under 20 MB to be safe across all providers.

Compression settings that work for email

• JPG quality 80–85% — Visually identical to the original on screen, typically 60–70% smaller.
• Max width 1920px — Sufficient for viewing and light printing. Reduces file size dramatically compared to full 4000px originals.
• Keep HEIC originals — Compress copies for email. Your originals stay full quality on your phone.

Format tips for email attachments

• Use JPG for photos — Universal support across all email clients and devices.
• Use PNG only for screenshots — Text and UI elements stay sharp. PNG photos are unnecessarily large.
• Avoid WebP — Most desktop email clients do not display WebP inline.
• Rename if needed — Some corporate filters block unusual extensions. .jpg is the safest choice.

When compression is not enough

If you need to send 20 or more full-resolution photos, email is the wrong channel. Alternatives:

• Cloud sharing — Google Drive, iCloud, or Dropbox links avoid attachment limits entirely.
• ZIP archives — Combine compressed JPGs into a ZIP. Some providers handle ZIPs better than dozens of individual attachments.
• Split across emails — Send batches of five to ten photos per message.

For broader compression techniques, read How to compress images without losing quality. For website-specific optimization, see How to compress images for your website.