Starturl

Starturl, more commonly written start_url in web development, refers to the entry point URL that a web application uses when it is launched. It is a key property in a web app manifest (manifest.json) for Progressive Web Apps (PWAs). The start_url defines the page that the user sees when they start the app from a home screen or app launcher, providing a predictable beginning state for the app experience.

In the manifest, start_url is specified as a URL, typically relative to the origin, and is expected to be within the app’s defined scope. The value determines what the app loads initially, and it may include query parameters to restore a particular state or view. Because the start_url is loaded in a standalone window (depending on the display mode), it influences the first impression and initial offline or online content presentation managed by the service worker.

Best practices include keeping the start_url within the manifest’s scope to avoid navigation outside the intended app boundaries, choosing a stable path to minimize breakage during updates, and ensuring that the URL works offline when supported by the service worker. Start_url can cooperate with other manifest fields such as scope, display, and background_color to deliver a cohesive, app-like launch experience.

Example values might be start_url: "/index.html" or start_url: "/home?source=app" within a manifest.json. While start_url is a standard field in PWAs, variations like starturl may appear in some documentation or tooling, though the canonical property uses the underscore form.