What it means
The account exists, but the user hasn't clicked the link in their confirmation email yet. Supabase won't let them log in until they do.
Why AI tools cause it
The AI built a sign-up form but never told the user to check their inbox. Often the email never arrived at all: Supabase's built-in email service only sends to members of your Supabase team and only 2 emails an hour, so real users don't get them.
The fix
- After sign-up, show a clear "Check your email to confirm your account" message instead of sending the user straight to the login page.
- For real users, set up your own email sender: Authentication → Emails → SMTP Settings (any provider such as Resend, Postmark or Brevo works).
- Check the confirmation link points at your live site, not
localhost(set Site URL under Authentication → URL Configuration). - To unblock one person now, run this in the SQL Editor:
update auth.users set email_confirmed_at = now() where email = 'their@email.com';
Only switch off Confirm email if you're happy for anyone to sign up with an address they don't own.
Paste this into your AI
Users see "Email not confirmed" when logging in to my Supabase app. After sign-up, show a "check your email" screen with a button that resends the confirmation using supabase.auth.resend. On the login page, catch this error and show a friendly message with the same resend button.
Still broken?
If emails still don't arrive after adding SMTP, check your email provider's logs and spam folders, and make sure your sending domain is verified with them.