Android Application Record (AAR)

What Is an Android Application Record?

An Android Application Record (AAR) is a special NDEF record (TNF 0x04, type "android.com:pkg") that forces Android devices to launch a specific application when scanning an NFC tagNFC tagPassive unpowered device storing data, powered by reader's RF fieldView full →. If the app is not installed, Android automatically opens the Google Play Store page for it.

How AAR Works

When Android reads an NFC tag with an NDEF message containing an AAR, it forces dispatch to the specified package name regardless of other records. This overrides normal intent resolution — even if multiple apps match the first record's data type, only the AAR-specified app receives the tag data.

AAR Record Structure

TNF: 0x04 (External Type)
Type: "android.com:pkg"
Payload: "com.example.myapp" (package name, UTF-8)

Common Patterns

URI + AAR (recommended):

Record 1: URI — "https://example.com/product/12345"
Record 2: AAR — "com.example.myapp"

Android opens the URL in the specified app. iOS (which ignores AAR) opens the URL in Safari — best cross-platform compatibility.

Text + AAR: For IoT configuration where only the companion app understands the data.

AAR Only: Simply launches the app without passing data.

Cross-Platform Behavior

Always include a standard URI record or text record as the first record so non-Android devices have meaningful behavior.

Memory Impact

An AAR consumes 25-50 bytes: ~7 bytes overhead (header + type) + 15-40 bytes package name. On NTAG 213 (144 bytes user memory), adding an AAR after a URI may consume 40-65% of capacity.

When to Use

Use AAR when the tag data only makes sense in your app, when you need guaranteed Play Store discovery for users without the app, or for app-exclusive features (loyalty, IoT control). When web fallback is acceptable, consider Android App Links (domain verification) instead — this avoids consuming tag memory.