An error state is the interface condition shown when a task, request, or system operation cannot complete as intended and the user needs explanation or recovery guidance.
A payment fails. A file upload is rejected. A user loses permission during a task. An API request times out.
The product should not simply display “Something went wrong.” It should help the user understand what they can do next.
Validation prevents or explains invalid input before a larger operation completes. An error state can describe a broader system or task failure.
Both should be specific and actionable.
An edge case is a condition. An error state is one possible UI response when that condition blocks success.
The user needs product meaning, not internal diagnostics.
Use neutral language and explain constraints clearly.
Recovery should not create more work than the original task.
When possible, provide retry, edit, alternate method, or support.
An error state asks: what failed, what is still safe, and how can the user recover?
Edge case · Loading state · Product state · Interaction design
Read Prototyping UX Design for failure and recovery examples.