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Constraints 0:28
A 28-second explainer of Constraints, narrated over the same demo you can try yourself.
Try the interactive Constraints demo
What this video covers
Constraints are design limits that prevent users from taking wrong actions, making the right choice the easiest path. Instead of telling users what to do and hoping they follow, you remove the option to act incorrectly - like a connector that fits only one way, a field that rejects invalid input, or a submit button that stays disabled until valid - so entire classes of error can’t occur.
Free text invites every typo, format and impossible date you can imagine - then you police it with error messages. Constrain the input instead and the bad states never arise: you can't pick a day that doesn't exist, can't type a letter into a number, can't submit until it's valid. The error isn't caught - it's designed out.
