A “best Firebase alternative” for phone login is the option that keeps your users verifying on Egyptian numbers without an SMS code screen. For many Flutter teams that is missed-call verification, not another global SMS API.
How to judge an alternative
- Does the user finish without a code?
- Can you keep Firebase for analytics and still swap phone auth?
- Is there a Flutter SDK and a server API?
- Are webhooks signed so your backend can trust completion events?
Shernova is not a full Firebase replacement
Shernova does not host your users, files, or push notifications. It is a verification layer. That is intentional: you keep ownership of accounts. Compare phone-verification only, not the entire Firebase catalogue.
Cut over without a risky rewrite
Ship the new flow behind a flag, verify webhooks on your server, then remove the SMS UI. The step-by-step is in Migrate from Firebase / SMS OTP.
Next step for developers
Shernova is a phone-verification layer for your app, not an end-user consumer app. Create a developer account, follow the quick start, then test the flow from the dashboard.