Loupe: What Apps Can See

A guided tour of the data any app can quietly read about you. Explore what's exposed, see why it's identifying, and decide what to do about it.

Ever wondered how advertisers recognize you across apps and websites? It usually comes down to fingerprinting: small, ordinary details about your device, combined until the mix is rare enough to point back to you.

Loupe lets you see those details yourself. It reads the same public iOS APIs that third-party apps use, showing you the raw data and explaining why it matters.

WHAT YOU CAN EXPLORE Trackers don't need your name, email, or location to recognize you. Your region, languages, settings, storage, and sensors create a pattern distinctive enough to follow you online. Loupe puts these readings in one place so you can see exactly what you're sharing.

THREE LEVELS OF ACCESS Loupe sorts every reading by how much access it takes:

• Passive: readable by any app with no prompt at all, from your time zone and keyboard languages to your battery and storage.
• Needs permission: readings that trigger an iOS prompt, like location, contacts, photos, and motion.
• Advanced: side channels that public APIs allow, like checking which apps you have installed, graphics checks in a hidden browser, and a record that survives reinstalling the app.

NOTHING LEAVES YOUR IPHONE Loupe reads everything on your device and keeps it there. Nothing is uploaded, synced, or shared unless you export it yourself. There are no accounts and no analytics.

A FEW THINGS YOU CAN LOOK AT

• The region, languages, and settings that hint at where you live and travel
• Your screen, graphics, storage, and battery details
• The name on a paired accessory, which often gives away your own name
• Which popular apps you have installed, worked out without any permission
• The exact second your device was set up or last erased

Loupe is built by Mysk, a security research team. It exposes the tracking surface of your iPhone, so you can decide what to do about it.