How Do I Compress a Photo for Email?
A phone photo is 3 to 6 MB, and most mailboxes cap attachments at 20 to 25 MB. Resize to 1,600 pixels wide and save at 80 percent JPEG quality for a file under 500 K.
In short
To shrink a photo for email, reduce its pixel dimensions and save it as a JPEG at moderate quality. Resizing a 4,000-pixel-wide phone photo to 1,600 pixels and saving at 80 percent quality typically cuts a 5 MB file to under 500 KB with no visible loss on a screen. Most phones offer a size choice when you attach a photo; choose Medium or Large rather than Actual Size.
A single photo from a modern phone is 3 to 6 MB. A dozen of them is more than most email systems will accept, and even one can take a minute to send on a slow connection. Shrinking them is easy and, for anything viewed on a screen, costs nothing visible.
Two ways a photo gets smaller
Fewer pixels. A phone photo is often 4,000 pixels wide or more. A laptop screen is around 1,500 to 2,000 wide; a phone screen is narrower than that. Resizing to 1,600 pixels wide throws away pixels nobody would see and cuts the file to roughly a sixth.
More compression. JPEG quality runs from 0 to 100. Phones save at around 90 to 95. At 80, the file is about half the size and the difference is invisible on screen. At 60, small artefacts start to appear around sharp edges. Eighty is the sensible default.
Do both and a 5 MB photo becomes 300 to 500 KB.
On a phone
When you attach a photo to an email on an iPhone, the mail app asks which size to send: Small, Medium, Large or Actual Size. Medium or Large is right for almost everything. Android mail apps and the Gmail app offer a similar choice, or resize automatically.
Messaging apps compress automatically and heavily, which is why photos sent through them look slightly soft when viewed large.
On a computer
Windows: right-click the photo, choose Send to, then Mail recipient, and pick a size. Or open in Photos, choose Resize, and pick Medium.
Mac: open in Preview, choose Tools then Adjust Size, set the width to 1,600 pixels, then Export as JPEG at a lower quality.
Or use a browser-based resizer that processes the image on your own machine, which avoids uploading the original anywhere.
Sending many photos
Past five or six, attachments are the wrong approach. Every recipient’s mailbox stores every copy, forwarding multiplies them, and size limits get hit. Put the photos in a shared album or a cloud folder and send the link. The email is a few kilobytes and the recipient chooses whether to download full quality.
What compression does not fix
A photo that was blurred, badly lit or badly framed stays that way. Compression removes detail; it does not add it. And a heavily compressed photo cannot be restored to full quality later, so keep the original if there is any chance you will want to print it.
A note on what travels with the file
Photos carry metadata: the camera, the settings, the date and time, and often the exact location where they were taken. Some phones strip location when sharing by email; many desktop programs do not. If the photo was taken at home or somewhere you would rather not disclose, check the metadata before sending, or use a tool that removes it.
Common questions
Will compression ruin the quality?
For viewing on a screen, no. A 1,600-pixel image fills a laptop display. Loss becomes visible only if the recipient wants to print large or crop heavily. Keep the original for that and send the compressed copy.
What about sending lots of photos?
Attachments are the wrong tool past a handful. Use a shared album or a link from a cloud service, which sends nothing but a URL and lets the recipient download full quality if they want it.
Does emailing a photo remove the location data?
Not necessarily. Many phones strip location metadata when sharing via email or messaging, but not all do, and desktop email clients generally do not. If the photo was taken somewhere private, check or remove the metadata before sending.
Sources
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- Canvas API MDN Web Docs
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