Compress an image for email
A smaller file. Ready to upload.
Drop an image here
Choose a JPG, PNG or WebP image.
Compression is lossy. Check small text and fine detail before using the result.
Your image stays on your device.
More images or another format
Process 1–10 images, one at a time. Up to 20 MB per image and 100 MB total. Files stay on this device.
Nothing is uploaded or saved by the app. Results remain in memory until cleared or the page closes.
Less weight. Same job.
Choose a photo or scan, set the file-size limit of your form, then download the result. The original is never changed.
Does my image get uploaded?
Images are processed in this browser, without image uploads, ads or analytics. Your language choice is stored locally. Public site files are saved only if you enable offline use; selected images and results are not saved.
What should I know?
One JPG, PNG or WebP. Choose JPG or supported WebP for a KB target; PNG optimization accepts PNG only, preserves pixels and has no KB target. PNG: up to 8 MP, 16,384 pixels per side and 64 MB decoded scanlines. Batch: 1–10 files, 20 MB each, 100 MB total. A verified basic HEIC opens in Safari, which decodes it natively; Chrome and Firefox cannot open HEIC. HDR, animation, unusual orientation and unsupported colour profiles are refused. Optional batch does not accept HEIC. GIF and SVG are unsupported.
How many compressed photos fit in one email
Mail services cap the size of a message, and attachments grow when they are sent because they are encoded as text. Microsoft gives the growth as 33% and Google as about 37%. We compressed our 25 photos to three targets and worked out how many fit under each limit.
Photos per message
| Service | Limit | Room for files | At 500 KB | At 1 MB | At 2 MB |
|---|---|---|---|---|---|
| Gmail | 25 MB | 18.2 to 18.8 MB | 36, 36 | 18, 18 | 16, 9 |
| Outlook.com | 25 MB | 18.2 to 18.8 MB | 36, 36 | 18, 18 | 16, 9 |
| Outlook (app) | 20 MB | 14.6 to 15.0 MB | 29, 29 | 15, 14 | 13, 7 |
| Yahoo Mail | 25 MB | 18.2 to 18.8 MB | 36, 36 | 18, 18 | 16, 9 |
| iCloud Mail | 20 MB | 14.6 to 15.0 MB | 29, 29 | 15, 14 | 13, 7 |
Room for files is the limit divided by 1.37 to 1.33. Each photo cell gives two counts: with our median photo, then with our largest result.
Source: our test on 2026-11-10 (harness eacd79c, site code eacd79c), headless Chromium 145 on a desktop Mac, 25 CC0 photos. How we test
Our photos at each target, Allow shrinking ticked
| Target | Photos | Fit | Median result | Largest result | Made smaller in pixels |
|---|---|---|---|---|---|
| 500 KB | 25 | 25/25 | 494.3 KB | 499.8 KB | 6/25 |
| 1 MB | 25 | 25/25 | 972.0 KB | 999.5 KB | 0/25 |
| 2 MB | 25 | 25/25 | 1.09 MB | 2.00 MB | 0/25 |
Source: our test on 2026-11-10 (harness eacd79c, site code eacd79c), headless Chromium 145 on a desktop Mac, 25 CC0 photos. How we test
How to send photos by email
- Add one JPG, PNG or WebP image above (or a HEIC in Safari). The target is 500 KB per photo.
- Leave Allow shrinking ticked and press Compress image. Repeat for each photo, or use the batch panel for up to 10 at a time.
- Add up the sizes. Keep the total under the room for files in the table, not under the service's own number.
- Attach and send. If the service turns the attachments into a link, the total was too big.
When an email attachment goes wrong
Gmail turned my attachments into a Drive link, but they were under 25 MB.
The limit counts the message after encoding, so 25 MB leaves about 18.2 MB for files. A user on Gmail's help forum saw the switch with files well under the limit (user report, Gmail community thread), and a Super User answer explains the same growth (user report, Super User).
The Outlook app will not send what Outlook.com accepts.
They are different products with different limits: Outlook.com allows 25 MB of attachments, and the Outlook app 20 MB for accounts such as Outlook.com or Gmail. Exchange business accounts default to 10 MB in the app. With our largest 500 KB result, the app's limit fits 29 photos.
How many photos can I attach?
At 500 KB each, 36 of our photos fit a Gmail message, counting the largest result. At 1 MB each, 18. At 2 MB, many photos came out under the target anyway, but the largest still allows only 9.
The official rules
From the official pages, with the date each one shows. An archived page was not reachable from our test machine, so we read a saved copy.
| Rule | Value | Source | Date |
|---|---|---|---|
| Gmail: attachment limit, personal account | 25 MB | Add attachments in Gmail | no date shown; read 2026-11-09 |
| Gmail: large-file fallback | attachments over the limit become a Google Drive link | Add attachments in Gmail | no date shown; read 2026-11-09 |
| Outlook.com: attachment limit | 25 MB | Sending limits in Outlook.com | 2026-04-21 |
| Outlook (app): email size limit in the Outlook app | 20 MB for internet accounts such as Outlook.com or Gmail; 10 MB default for Exchange accounts | Reduce attachment size to send large files with Outlook | 2026-04-09 |
| Yahoo Mail: attachment limit (incoming and outgoing) | 25 MB | Message size limits in Yahoo Mail | no date shown; read 2026-11-09 |
| iCloud Mail: message size limit | 20 MB (up to 5 GB with Mail Drop) | Mailbox size and message sending limits in iCloud | 2025-03-17 |
| Microsoft 365: encoding overhead | 33% increase outside Microsoft datacenters; OWA allows 25% less than the configured limit | Exchange Online limits | 2026-10-19 |
| Gmail: receiving size limit and encoding overhead | 50 MB (Enterprise Standard) or 70 MB (Enterprise Plus), measured after encoding (~37% increase) | Gmail receiving limits in Google Workspace | no date shown; read 2026-11-09 |
Other pages for this job: Compress image for Discord · Compress image to 200 KB · Compress image