Design the error states first

Every design review starts with the screen where everything works. We now start with the screen where it does not: the wrong password, the failed payment, the lost connection.

Errors are where trust is won

When a payment fails, people need to know three things: did money leave my account, what do I do now, and is my data safe. A vague red banner answers none of them.

Error states are also where security and design meet. A sign-in error that says the email does not exist tells an attacker which accounts are real. Our researchers sit in these reviews for exactly that reason.

What every error screen needs

• What happened, in plain words.
• What the person can do next, as a button.
• What did not happen, such as no charge.
• Nothing an attacker could use.

Designing these first takes about a day per product. It saves weeks of support tickets later.