Edit the expression up top, watch every test row light up where it matches. Captures land in a column you can copy.
/^([a-z0-9._]+)@([a-z0-9.-]+)\.[a-z]{2,}$/ilisa@beste.devlisaalex.turner@workspace.ioalex.turnernot-an-email—maria_99@beste.comaria_99missing@tld—robin@hello.worldrobinBrowser-chrome card hosting a regex playground — pattern + active flag pills up top, test rows with inline match highlights and capture column, summary footer. Every label is editable; no media props required.