Progressive enhancement is a development strategy that delivers a core, functional experience using plain HTML and CSS, then layers on richer features for browsers that support them. It ensures that every visitor can access the essential content, while those with modern capabilities receive an enhanced interaction.
Why it matters
Clients benefit because their site remains usable for all visitors, regardless of device or browser, reducing support costs and protecting brand reputation when users encounter older technology or disabled scripts.
How it works
Developers start with semantic markup and basic styling, then add optional CSS features using @supports queries and JavaScript enhancements guarded by feature‑detection libraries such as Modernizr. Each layer checks for support before executing, allowing unsupported environments to fall back gracefully.
The mistake people make
A common error is to rely on heavy JavaScript as the foundation and then try to strip it back for older browsers, which often leaves the site broken when scripts fail or are disabled. This results in lost functionality and a poor user experience for a segment of the audience.
