APK or AAB: which file do you need?
Choose APK to test an app on a device. Choose AAB for a separate app-store publishing workflow.
APK: installation and testing
An APK is an Android installation package. Use it to test the generated app on supported Android devices and share through appropriate distribution channels. Device settings and distribution requirements still apply.
AAB: publishing
An Android App Bundle is a publishing format. A store such as Google Play uses the bundle to produce packages for supported devices. It is not a file you normally tap to install directly on a phone.
Both formats are free here
Web2Apk builds APK and AAB output locally without a login or export fee. Save the project and keep its signing-key backup, whichever output you choose.
A file is not an approval
A valid package does not guarantee acceptance by a store. Developer verification, signing requirements, testing, policy compliance, and the store listing are separate responsibilities. Check the current requirements before distributing your app.