30 / INPUT
Inline Validation Timing
The problem
Validating while you're still typing screams errors before you've finished, but waiting until submit is too late.
The solution
Validation waits for blur (or a pause), and confirms when valid.
Experiment
Task: Type an email, then leave the field.
NAIVE
THOUGHTFUL
stateidle
debounce600ms
Play with the values
600ms
How it works
Seen in
Email fields
Format errors appear after you finish, not mid-address.
Password creation
Requirements confirm as met rather than flashing errors early.
Usernames
Availability checks run on pause, not each letter.
Payment forms
Card fields validate on blur to avoid premature errors.