How to compress photos on iPhone and Android

A modern phone camera writes 3–8 MB per photo. Nothing about that is wrong — the file is designed to survive cropping and printing. It is simply much larger than an email attachment, a marketplace listing or a web page needs.

You do not need another app for this. A browser can do the whole job on the device.

Before you start: what not to do

• Do not take a screenshot of the photo. It looks worse, it usually gets bigger, and it strips the original detail for good.
• Do not select the photo in your gallery and share it into a chat app as a way to shrink it. Chat apps re-compress unpredictably, and the copy you send is the copy you keep.
• Do not delete the original until you have confirmed the compressed version is good enough.

Doing it in the browser (iPhone and Android)

1. Open the image compressor in Safari or Chrome on your phone.
2. Tap the upload area. Your phone will offer the photo library or your files — either works.
3. Set Resize to the size you actually need. For something that will be viewed on a phone, fit within 1280 pixels is generous; for a thumbnail or an upload form, 800 is usually plenty.
4. Choose a compression level. Normal is almost always indistinguishable at these sizes.
5. Check the "Compressed size" figure against your limit, then tap download.
6. Sending several photos? Upload them together and download one ZIP file.

All of the processing happens on the phone itself. The photos are not uploaded to a server, which matters both for privacy and for your mobile data.

iPhone specifics

If you use iCloud Photos, your phone may hold a smaller "optimised" copy of an older picture and download the full-resolution version when you open it. If a photo looks unexpectedly small when you compress it, check that the full-resolution version has finished downloading first.

Also worth knowing: iPhone HEIC files are efficient, but plenty of websites and forms still reject them. Converting to JPG while you compress solves both problems at once — set the output format to JPG.

Android specifics

Gallery apps on Android often have their own share-based "resize" option. It is convenient, but the naming is vague and the result is whatever the app decides. Going through the browser gives you an explicit size and an explicit quality level, which is what you want when a form has a hard limit.

What sizes should you aim for?

• Sending to a friend or family member — 1600 pixels on the long edge, quality Normal. Usually 200–500 KB and it looks perfect on a phone screen.
• Email attachment — 1200–1600 pixels. Keep the total of all attachments under about 15 MB to stay clear of every provider's limit.
• Marketplace or classified listing — 1600 pixels. Most platforms re-compress anyway, so there is no gain in uploading more.
• Social post — 1080–1440 pixels is what the platforms serve. Anything more is thrown away on upload.
• Print — do not compress. Keep the original resolution.

Frequently asked questions