An error message should communicate what caused the problem, if possible include how to prevent or fix it, and suggest what to do next.
- Be kind and don’t use technical language. For example, no “Internal error: null.”
- Use sentence case with punctuation.
- Include a CTA, whether a link or button.
- Be careful with humor. Error messages can be a place to show some personality but most humor doesn’t translate globally and can be perceived as fake or unempathetic.
List of standard error messages for reference.