Browsersupplied

Browsersupplied is a term used to describe data, capabilities, and resources that originate within a web browser and are exposed to a web page or script. It contrasts with server-supplied content delivered over HTTP, such as HTML, CSS, and JSON from a remote server. Browsersupplied information helps scripts adapt behavior and presentation to the user’s environment.

Common examples include the user agent string and locale information (for example, navigator.userAgent and navigator.language), which can influence content formatting, language selection, or feature availability. Browser-provided display and input context, such as screen dimensions, viewport size, devicePixelRatio, and touch or pointer support, guide responsive design and interaction patterns. Web APIs expose additional capabilities, including storage options (cookies, localStorage, sessionStorage, indexedDB), permission status for features like geolocation or notifications, and device or browser feature flags (for instance, WebGL support or service worker availability).

Browsersupplied data is typically used for progressive enhancement, feature detection, localization, offline behavior, and tailoring experiences to the user’s device. It remains distinct from server-supplied data, which originates from the server and can be controlled or altered independently of the client. Because browser information can vary between users and can change over time, developers often rely on robust feature detection rather than assumptions about a specific browser.

Privacy and security considerations are important with browsersupplied data. Access to sensitive information, such as precise geolocation, requires explicit user consent, and some data can be spoofed or limited by the user’s privacy settings.