How deep links work
When someone taps a deep link, the operating system works out which app can handle it and opens the
right screen directly. Without deep links, every tap on a link from a push notification or an email
lands on the home screen — and the person is lost.
Three generations of the technology:
URI schemes (myapp://product/12345) — the oldest type. They work only when the app is
installed; if it is not, the result is an error with no fallback. Most browsers do not support them
directly.
Universal Links (iOS) / App Links (Android) — ordinary HTTPS links
(https://shop.example.com/product/12345). If the app is installed and configured, the app opens on
the right screen. If not, the web version opens. The reliable modern standard.
Deferred deep links — a mechanism that carries the parameters through installation. Covered in a
separate entry.
Where deep links are critical in e-commerce
| Scenario | Without a deep link | With a deep link |
|---|---|---|
| Price-drop push | The home screen opens | The specific product page opens |
| Email with recommendations | The browser opens | The right screen opens in the app |
| An ad for a specific product | The catalogue opens | The product page opens immediately |
| Abandoned cart | An empty screen opens | The cart opens with the items in it |
Every extra step between intent and the target action costs conversion. Deep links remove those
steps.
Setting up Universal Links: what is needed
On the server side, publish at the standard path:
– iOS: https://shop.example.com/.well-known/apple-app-site-association
– Android: https://shop.example.com/.well-known/assetlinks.json
Those files list the App IDs and the URI patterns the app can handle. Without them, or with an error
inside them, links open in the browser.
Tip: retest deep links after every app release and every server-side change. A broken deep link
in a push campaign means the entire campaign budget is thrown at the home screen.
Common errors
No fallback for an app that is not installed. The person sees an error instead of the web version
or the App Store.
The deep link points at a screen that no longer exists. The screen was renamed in an app update;
the link in the push was not. The person lands on the home screen or gets an error.
Deep links are not tested on both platforms. iOS Universal Links and Android App Links are
different mechanisms that need separate configuration and separate testing.