My customers say they can't sign up or log in. What do I check first?

Open your real address in a private window. Try to sign up with a new email address, and try to log in with an account you already had.

Write down exactly what you see: a blank page, an error message, a page that does not exist, or nothing happening. “It doesn't work” rarely says which. What you see tells you which step below to read first.

Open your sign-up page and your log-in page. Check that the email box, the password box and the button are on the page.

After a change made by an AI tool, a page can lose a form or a button without any error message. If something is gone, tell your AI tool what was on the page before and ask it to put it back.

With email confirmation on, a new customer has to open the confirmation email before they can sign in. Lovable's documentation says to ask people to check their spam folder first, because emails from new domains often land there. It also says that if many people sign up at once, your project may reach its hourly email limit (Lovable Docs: Email authentication).

Signing in again does not send a new confirmation email. The same page says a customer can get a new one by signing up again with the same address.

Open a real confirmation email and hover over the link. It should start with your real web address, not “localhost”. See Why isn't Supabase sending my confirmation email?

Sign-in services such as Supabase only send people back to addresses on a list you control. Lovable's documentation says that if sign-in works in preview but breaks on the published app or a custom domain, the missing address in that list is usually the reason. For apps on Lovable's built-in backend, Lovable adds your published address and custom domain to the list. If your app uses your own Supabase project, you add the address in that project's authentication settings (Lovable Docs: Users and authentication).

Add your address with and without “www.” if both open your site. See Sign-up worked when I tested it, but new customers can't sign up on my live site.

If sign-in broke right after a change, even a small one to the sign-in page, look at what you asked for. Then tell the tool exactly what broke, and ask it to change nothing else. You can paste this:

Sign-up or log-in is not working on my live site https://yourdomain.com. What I see: [describe exactly, for example: the confirmation email link opens a page that does not exist].
Do not change anything except what is needed to fix this.
1. Check that my live address, with and without www, is in the list of allowed redirect addresses.
2. Check that the confirmation email link points to my live address, not to localhost.
3. Check that the sign-up and log-in pages still have their email box, password box and button.
4. Tell me which files you changed and why.

Heedza opens your home page, follows its links to find your sign-up, log-in and payment pages, and opens them again on a schedule. It checks that each page opens and shows its email box, log-in form or Pay button. If one does not, it sends you a picture of the page and a fix to paste into your AI tool. It never signs in, never submits forms, never types a card number and never clicks Pay.

Because Heedza never signs in, it cannot see an error that only appears after someone presses the Log in button, and it cannot see whether a confirmation email arrives.

Use the free scan at the bottom of this page. Paste your live web address. It opens your home page, looks for secret keys in its code, checks a few private files and looks at what search engines see. No account is needed.