Web
A category of file formats covered by Format Atlas.
About this category
CSSCSS is a stylesheet language for document presentation. Selectors and declarations control how elements look, while HTML provides the page structure.HTMLHTML is a markup language for describing the structure and meaning of web pages. Keep presentation in CSS and behavior in JavaScript when needed.WebAssembly module`.wasm` is a common extension for a binary module defined by the WebAssembly Core Specification. WebAssembly is a portable low-level code format used beyond the web, but a file is not executable everywhere by itself. It needs a compatible runtime, and available features and host APIs depend on the embedding environment.Web App ManifestA Web App Manifest uses JSON to describe a web application. It can set a name, icons, start URL, and display mode, but its behavior depends on browser and platform support.