How to send your Android app to testers: APK, Firebase or Play

The fastest route. Build a signed .apk and share it as a link (Google Drive, Dropbox, your own site) or in a message. The tester opens it on their phone; the first time, Android asks them to allow installs from that app ("Install unknown apps"), then it installs.

For an update, send a new APK signed with the same key and with a higher build number. It installs over the old one and keeps the tester's data. Corenna raises the build number after every successful build, so this happens by itself.

The trade-offs: testers have to trust a file, Play Protect may warn them about an unknown developer, nothing updates automatically, and you collect feedback yourself. It suits a handful of friends or a quick demo.

Google is requiring apps installed on certified Android devices to be registered by verified developers. As of October 2026, according to Google:

• Since August 2026, students and hobbyists can open a free limited distribution account, with no government ID or fee, that shares an app with up to 20 devices.
• Since September 30, 2026, the protections apply to apps installed from participating stores in Brazil, Indonesia, Singapore and Thailand.
• Google plans to expand verification to all apps on certified Android devices in 2027.
• Apps from unregistered developers can still be installed through an advanced flow for power users, or with ADB.

The rules are still changing. Before you rely on sharing APKs widely, check Google's developer verification page.

Firebase App Distribution is Google's tool for exactly this, and it costs nothing on Firebase's plans. Upload the APK (or the AAB) to a Firebase project, add your testers' email addresses, and each tester gets an email that walks them through installing it. Every new build you upload reaches the same list. It needs a Firebase project, but no Google Play account.

Needs a Google Play developer account and the .aab. Testers install from the Play Store and get updates the normal way.

• Internal testing: up to 100 testers per app, and a new release reaches them within minutes.
• Closed testing: larger groups, by email list or Google Group. For a personal developer account created after November 13, 2023, it is also the step Google requires before production: at least 12 testers for 14 days.

Google requires a brand-new app's first release to be created by hand in the Play Console. After that, Corenna can send each new .aab to the internal or closed track with release notes, from a laptop or your phone.

• Two or three friends, today: send the APK.
• A test group that needs every new build: Firebase App Distribution.
• You will publish on Google Play: start a closed test now. On a newer personal account the clock for production access only starts when testers are in.

• Same signing key, always. A build signed with a different key will not install over the old one. Corenna stores your keystore encrypted, and you can download it and its password to keep a backup.
• Higher build number. Android and Google Play compare the version code; Corenna raises it after every successful build.
• Same package ID. A different ID installs as a second, separate app.