Progressive Enhancement

Progressive Enhancement is a design philosophy that ensures a basic, functional experience for all users, regardless of their device or browser capabilities, while providing enhanced features for users with more advanced technologies. The approach focuses on building a solid foundation that can be progressively enhanced for better user experiences across a range of devices.

Progressive enhancement is the principle that explains why some web apps work on slow connections and old devices while others break entirely. For global SaaS products serving customers in developing markets or in corporate environments with locked-down browsers, progressive enhancement is the difference between having and losing those customers. It also provides resilience — when JavaScript fails to load (which happens more than developers realize), a progressively enhanced product still works.

GOV.UK's design principle is progressive enhancement — their forms work with no CSS and no JavaScript, using plain HTML. This ensures UK government services are accessible to everyone regardless of device or connection quality, which is a legal accessibility requirement for public services.