webclients

A web client is software that retrieves, renders, and interacts with resources hosted on web servers. It runs on a user’s device and sends requests via HTTP or HTTPS. The term contrasts with a web server and emphasizes the client side of the client–server model. The most familiar web clients are web browsers, but mobile apps that use web APIs and embedded WebView components are also common.

Function and operation: A web client fetches documents, renders content, and runs scripts to present a user interface. It may communicate asynchronously with servers using AJAX or the Fetch API, enabling dynamic interfaces without full page reloads. Modern web clients can be single-page applications or traditional multi-page apps and rely on standards such as HTML, CSS, and JavaScript.

Types and examples: Web browsers (Chrome, Firefox, Safari, Edge) are the primary web clients. Headless browsers (Puppeteer, Playwright) automate tasks for testing. Embedded WebViews (Android WebView, iOS WKWebView) render web content inside native apps. Some clients are thin and rely on remote services, while others are rich clients with significant local logic.

Security and privacy: Web clients operate under the same-origin policy and use measures like CORS, Content Security Policy, and sandboxing. Session state is managed via cookies, localStorage, or tokens (OAuth). Performance is aided by caching, service workers, and offline support.

Relation to servers and APIs: A web client is the user-facing component that consumes resources exposed by servers or APIs, often via REST, GraphQL, or other protocols. The term covers a range of technologies and architectures used to deliver interactive web experiences.