Progressive Web App Manifest

Definition

The Web App Manifest is a JSON file linked from a web page that describes a Progressive Web App's name, icons, colors, and display behavior, enabling browsers to let users install it as an app-like experience on their device.

Overview

The Web App Manifest is the metadata layer that turns an ordinary website into something a browser can offer to install like a native app. Linked from an HTML page via `<link rel="manifest" href="/manifest.json">`, it's a JSON file with standardized fields: `name` and `short_name` for how the app is labeled, `icons` (an array of image sizes used for the home-screen icon, splash screen, and app switcher), `start_url` specifying which page opens when the app is launched, `display` controlling whether the app opens in a full standalone window, a browser-like tab, or fullscreen, and `theme_color`/`background_color` for the status bar and splash screen appearance. The manifest alone doesn't make a site fully installable in most browsers; it typically needs to be paired with a Service Worker (registered separately in JavaScript) that provides at least basic offline caching, which together with the manifest and being served over HTTPS satisfies most browsers' installability criteria. Once those conditions are met, browsers can surface an install prompt — Chrome's `beforeinstallprompt` event lets a site customize when and how that prompt is shown — and once installed, the app appears in the device's app list or home screen, launches without browser chrome (depending on the `display` mode), and can register file handlers, share targets, and shortcuts, all also configurable through additional manifest fields. The manifest format is standardized by the W3C as part of the broader Progressive Web App (PWA) effort, and while support and installability nuances differ somewhat between Chrome, Edge, Safari, and Firefox — notably iOS Safari's PWA support has historically lagged and imposed extra constraints — the core manifest fields are broadly interoperable. Beyond enabling installation, the manifest also affects how a site is presented if a user adds it to their home screen even without a full install flow, making it a low-effort addition that improves the app-like feel of a web app across a range of browsers and devices, even for teams not pursuing a full offline-capable PWA.

Specification

• JSON file linked via <link rel="manifest"> describing app metadata
• name/short_name fields controlling how the app is labeled on the device
• icons array defining home-screen, splash-screen, and app-switcher images at multiple sizes
• display field controlling standalone, fullscreen, minimal-ui, or browser display modes
• theme_color and background_color for status bar and splash screen styling
• start_url specifying the entry page when the installed app is launched
• Works alongside a Service Worker and HTTPS to satisfy browser installability criteria
• Supports additional fields for shortcuts, file handlers, and share targets

Use Cases

History

The Web App Manifest is a JSON file (commonly manifest.json) that gives a web application the metadata a browser needs to install it like a native app — its name, icons, theme and background colors, and display mode. It is a W3C specification, and together with a service worker it forms the minimum requirement for a Progressive Web App (PWA) to be installable. Once installed via a manifest, a PWA gets a home-screen icon and can launch as a standalone window rather than inside a browser tab. The broader idea took its name in 2015, when designer Frances Berriman and Google Chrome engineer Alex Russell coined the term "progressive web apps" for sites that use these modern capabilities to behave like installed applications.

Frequently Asked Questions

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