
Foolproof
Error-proof
Use 'foolproof' for methods that leave no room for error.

He installed a foolproof security alarm at home.
User-Friendly
Describe processes or items that are extremely easy to use.

The cake mix is foolproof — just add water.
Confidence Inspiring
Show that something gives people confidence because it's less likely to go wrong.

Her foolproof reputation made her the favorite candidate.
Compare with
BulletproofDependableFallibleGuaranteeImpeccableReliableSecureUnfailing
WordUp Chrome Extension
As you browse the web instantly look up words you don’t know.
Get Chrome Extension