Compress Images for Email — Stop Attachment Size Limits
Gmail blocks attachments over 25MB. Outlook blocks over 20MB. Most corporate email systems have even tighter limits. If your screenshot is 8MB, you have a problem before you even hit send.
Here's how to compress images for email without making them look terrible.
Email Attachment Size Limits
| Provider | Limit |
|---|---|
| Gmail | 25 MB |
| Outlook | 20 MB (15 MB in some versions) |
| Yahoo | 25 MB |
| Apple Mail | Unlimited (but recipient limits apply) |
| Corporate/Exchange | Varies (often 10 MB) |
Rule of thumb: Keep individual attachments under 5MB. Use a shared link (Google Drive, Dropbox) for anything larger.
Image Type Matters
Not all images are equal for email:
- Photos from phone — 4000×3000 pixels, 8–15MB. Needs serious compression.
- Screenshots — 1920×1080 pixels, 500KB–3MB. Minor compression usually enough.
- Product photos — varies widely. Target 200–500KB each.
- Logos/graphics — usually small. Only compress if over 500KB.
Compress to JPG for Photos
JPG is the right format for email photos. It's compact, universally supported, and looks fine at reduced quality.
Target settings for email:
- Dimensions: 1600px on the longest side
- Format: JPG
- Quality: 75–80
A 12MB phone photo becomes 200–400KB. Perfect for email.
Compress to WEBP for Maximum Efficiency
If the recipient can open it (most modern email clients can), WEBP at quality 75 gives you:
- 50–60% smaller than equivalent JPG
- Same visual quality
- Less data used
For internal business email where you know the client software, WEBP is excellent. For unknown recipients, stick with JPG for safety.
How to Check Your Attachment Size
Before hitting send, check:
- Attach the file(s) to your email
- Look at the total size shown (usually in the bottom of the compose window)
- If it's over 10MB, compress before sending
Alternative: Link Instead
For large image sets:
- Upload to Google Drive / Dropbox
- Share the link in your email
- Works for 100MB+ of images without attachment limits
This is the professional standard for image-heavy communications.
Quick Compress Guide
| Image type | Max email size | Best format | Target dimensions | Quality |
|---|---|---|---|---|
| Phone photo | 500KB | JPG | 1600px long | 75 |
| Screenshot | 200KB | JPG or PNG | 1200px wide | 80 |
| Product photo | 300KB | JPG | 800px wide | 78 |
| Logo/graphic | 100KB | PNG | actual size | lossless |
Common Mistakes
Mistake 1: Sending a full-res 4K photo in an email The recipient doesn't need 4000×3000. Resize to 1600px on the longest side first.
Mistake 2: Using screenshots at full resolution A 1920×1080 screenshot at 500KB compressed to 80% JPG is 80KB. That's fine for email. But if it's 3MB PNG, compress it.
Mistake 3: Over-compressing to 30% quality Yes, it's small. But it also looks like garbage. Don't do this. 75% quality is the minimum; 80% is better for any image with text or faces.