Nielsen's 10 Usability Heuristics
Most interface problems aren't mysterious. Someone clicked the wrong button, didn't know the system was loading, or couldn't find their way back. Jakob Nielsen and Rolf Molich noticed this in 1990 - usability failures cluster around the same recurring causes. The ten heuristics they published are still unchanged, because human cognition hasn't changed.
Ten heuristics, one bus ride. By your stop, you will see them in every app on your phone.
They're not a checklist you apply at the end. They're a lens you develop over time, until violations start jumping out at you before users ever touch the product.
The 10 Heuristics
1. Visibility of system status.When a system goes silent, users panic. Loading spinners, progress bars, and confirmation toasts all do the same job: prove the system received your action and is doing something about it. Trust is built through continuous, honest feedback - and broken the moment the interface goes quiet.
2. Match between system and the real world.Your mental model of the system is not your user's. The moment you write “submit query” instead of “search,” you've introduced friction. Use the words, metaphors, and conventions of your user's world - not your codebase.
3. User control and freedom.People explore cautiously if they fear getting stuck. Undo, cancel, and back aren't edge cases - they're the safety net that makes exploration feel safe. Without them, users get timid, and timid users never find your best features.
