What your photos leak: EXIF metadata and GPS

Many photos you take with your phone carry a hidden payload.

Inside the file, next to the pixels, there can be a block of metadata called EXIF (Exchangeable Image File Format). It can record when the photo was taken, which device and settings you used, and exactly where you were standing.

Send that file to someone, and they can read all of it. Let’s look at what’s in there.

What EXIF stores

EXIF data lives in a segment of the JPEG file (the APP1 segment, right after the file header). It’s organized in groups of tags:

• Camera: make and model (“Apple”, “iPhone 15 Pro”), orientation, software version
• Exposure: shutter speed, aperture, ISO, focal length
• Timestamps: local capture time down to the second. Classic EXIF timestamps usually have no timezone unless separate offset tags are present
• GPS: latitude, longitude, altitude, sometimes even the direction the camera was pointing

The camera settings are harmless. Photographers rely on them.

The timestamps and GPS coordinates are the problem.

How GPS ends up in your photos

When you first opened the camera app on your phone, it asked for location permission. If you tapped yes (most people do), every photo since then has your coordinates embedded in it.

The precision is not “somewhere in Milan”. Six decimal places in decimal degrees give a precision of roughly 10 centimeters. A photo taken at home pinpoints your home.

The coordinates are stored as three rational numbers (degrees, minutes, seconds) plus a reference letter (N/S, E/W). Converting to the decimal format you’d paste into a map is straightforward:

decimal = degrees + minutes/60 + seconds/3600

So a photo tagged 45° 26' 13.2" N, 12° 20' 4.5" E resolves to 45.437000, 12.334583, a specific spot in Venice. Anyone with the file can do this in seconds.

Who strips it, who doesn’t

Here’s the part most people get wrong. The big social platforms strip EXIF on upload:

• Facebook, Instagram, X: stripped (though the platform itself reads it first)
• WhatsApp: stripped when sent as a regular photo

But plenty of common channels preserve it:

• Email attachments: full EXIF, untouched
• WhatsApp “send as document”: preserved (the quality-preserving option people use on purpose)
• Your own website or blog: whatever you upload is what gets served
• Chat and collaboration attachments: behavior varies by service, client, and whether the image is recompressed
• Cloud storage links (Dropbox, Drive): the original file, GPS included

Anything that treats your photo as a file may keep the metadata. Anything that recompresses it for a feed usually strips it. Check the downloaded copy instead of assuming a service removes EXIF.

Selling something on a classifieds site with photos taken at home? If the site doesn’t strip EXIF, your listing includes your address.

How to check what a photo leaks

You can inspect EXIF entirely in the browser without uploading the photo anywhere. I built an EXIF viewer that reads the file locally with the FileReader API, parses the JPEG segments, and shows every tag, including GPS coordinates plotted on a map. The image never leaves your computer.

The browser reads the file into an ArrayBuffer, finds the APP1 marker in the JPEG bytes, and walks the TIFF directory structure inside it. If you want to build something similar, I wrote about the FileReader object and the Blob object. It’s a nice exercise in reading binary data in JavaScript.

How to strip it

On iOS, the fastest option is built in: in the share sheet, tap Options at the top and turn off Location before sending.

To remove metadata from files you already have, you have a few options:

• Client-side, in the browser: the EXIF viewer mentioned above also strips metadata. The trick is simple: draw the image onto a canvas and re-export it. The canvas only knows pixels, so the new file has no EXIF at all.
• Command line: exiv2 rm photo.jpg removes everything in place. I covered this approach in remove EXIF data from images, including the ImageOptim app for Mac.
• Screenshot the photo: crude, but a screenshot is a new image with no EXIF from the original. You lose quality.

One caveat on the canvas method: re-encoding a JPEG loses a little quality. For photos going on the web that’s irrelevant. For archival originals, keep the original and strip a copy.

My advice

You don’t need to be paranoid about this. GPS in photos is genuinely useful because your photo library uses it to build maps and memories.

The rule I follow: metadata is fine on photos that stay in my library, and gets stripped from photos that leave it as files. Before sending a photo by email, posting it on my own site, or attaching it anywhere that isn’t a big social platform, I check it. It takes ten seconds, and it’s the difference between sharing a photo and sharing your home address.

Want me to talk about your product? You can sponsor this site.