Should I use alert box or just helper?

Question

I have a case, related to inquiring a sequence of number. User can look up to that number and processed that into another task. But not all number can be inquired in this system (due to some rules). I thought to give it notifications if that number can't be inquired using helper (because user can still also filled the fields when you clear the number and type another one). Is it right?

or should I use alert box (which can be gone in few seconds)?

this number is inquired when user done typing the number (not when submitting the form). Thank You!

Answer 1

Please do not use the red Alert message (screenshot #2).

The described use case is for inline validation. If needed, you can add help or hint with instructions on where to get information or how to add value, etc.

Please review the following articles, where you will find a comprehensive answer to your question:

1. The Trick to Writing Error Messages That Won’t Frustrate Users
2. The Best Place for Error Messages on Forms
3. How to Make Your Form Error Messages More Reassuring
4. Why Users Make More Errors with Instant Inline Validation