Supabase email templates: customize per email type and test the variables before launch

Supabase email templates: customize before your users see the defaults

Auth emails (confirmation, magic link, recovery, invite) come from default templates with Supabase branding. Agents leave them until launch day, when fixing them means resending flows under pressure.

Checkable procedure

1. In the dashboard go to Authentication, Email Templates. There is one template per email type: confirmation, magic link, recovery, invite, and others. Customize each one you use, not just signup.
2. Use the documented template variables for the action link in each template. Hardcoding a URL instead of the variable breaks when the Site URL changes between environments.
3. Set the sender name and confirm the from address. The default sender is fine for dev and wrong for production trust.
4. Keep the emails short and single-purpose. One link, one action. Agents love adding marketing copy to transactional auth emails; it hurts deliverability.
5. Send a real test email for each template type and click the link. Confirm it lands on your app, completes the action, and the session is established.

Quick test

Trigger each email type to a real inbox, not a plus-addressed dev inbox. Click every link and complete the flow. If a link 404s, the template URL does not match your Site URL config.

Verified against live Supabase docs 2026-09-26: https://supabase.com/docs/guides/auth/auth-smtp