NielsenErrorRecovery [principle] v1.0.0

Nielsen Heuristic 9: error messages should be expressed in plain language, precisely indicate the problem, and constructively suggest a solution.

Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution.

Attributed To

Jakob Nielsen, 1994

Applies To

• form validation messages: field-level errors with specific correction guidance
• network/API errors: translating failures into user-actionable next steps
• empty states after failed searches: explaining why results are empty + what to try
• authentication errors: distinguishing 'wrong password' from 'account not found'
• payment failures: explaining decline reason in terms of user action required
• 404 / dead-link pages: offering navigation alternatives rather than just the error code

Counter Examples

• A form that returns a generic 'Something went wrong. Please try again.' with no indication of which field failed or why.
• A login page that returns 'Invalid credentials' for both wrong password and non-existent account — security rationale is valid, but no recovery path is offered for forgotten email.
• An API error dialog showing 'HTTP 500 Internal Server Error' with a Close button and nothing else — no retry, no support link, no explanation.

NielsenErrorRecovery [principle] v1.0.0

Nielsen Heuristic 9: error messages should be expressed in plain language, precisely indicate the problem, and constructively suggest a solution.

Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution.

Attributed To

Jakob Nielsen, 1994

Applies To

• form validation messages: field-level errors with specific correction guidance
• network/API errors: translating failures into user-actionable next steps
• empty states after failed searches: explaining why results are empty + what to try
• authentication errors: distinguishing 'wrong password' from 'account not found'
• payment failures: explaining decline reason in terms of user action required
• 404 / dead-link pages: offering navigation alternatives rather than just the error code

Counter Examples

• A form that returns a generic 'Something went wrong. Please try again.' with no indication of which field failed or why.
• A login page that returns 'Invalid credentials' for both wrong password and non-existent account — security rationale is valid, but no recovery path is offered for forgotten email.
• An API error dialog showing 'HTTP 500 Internal Server Error' with a Close button and nothing else — no retry, no support link, no explanation.

Sources

Examples

• Stripe's payment decline messages distinguish between 'Insufficient funds — try a different card' and 'Card blocked by issuer — contact your bank', giving users a clear recovery path.
• GitHub's 404 page suggests checking the URL, searching repositories, and links to recent activity — it doesn't just display a number.
• Slack's 'You're not in any channels yet' empty state pairs the error condition with a 'Browse channels' CTA — the message and the recovery action are co-located.

Source

• Jakob Nielsen, 'Heuristic Evaluation', in Nielsen & Mack (eds.), Usability Inspection Methods (1994)
• https://www.nngroup.com/articles/ten-usability-heuristics/