Home › Build error fixes › Android / Gradle

Package name already used

Android / Gradle · last reviewed 2026-11-10

The error looks like this

You need to use a different package name because "com.helloworld" already exists in Google Play.

Why it happens

applicationId is taken on Google Play (often a template default like com.helloworld).

How to fix it

Change applicationId in android/app/build.gradle (Expo: android.package) to a unique reverse-domain ID.
It can never change after the first upload, so choose carefully.

Not sure this is your error? Let ReleaseMedic read the whole log

Build logs are long and the last line is rarely the real cause. ReleaseMedic finds the first real error, explains it and gives the steps — free, and the log never leaves your computer.

$ npx releasemedic log build.log

Or pipe a build straight in: cd android && ./gradlew bundleRelease 2>&1 | npx releasemedic log -

Catch it before you build

Most release errors come from project settings you can check in seconds — signing, SDK levels, privacy manifests, permissions, push and login setup.

$ npx releasemedic