# Web app manifest

> A web app manifest is a JSON file, usually served at /manifest.json and linked from the page head, that tells the operating system how a web app should…

Source: https://northerngo.com/glossary/web-app-manifest/
Language: en
Updated: 2026-08-28

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**A web app manifest is a JSON file, usually served at /manifest.json and linked from the page head, that tells the operating system how a web app should behave when installed: its name, its icons, the address it opens at and whether it launches in its own window or a browser tab.**

### The fields that actually matter

A manifest is short, and most of it is metadata the operating system reads once at install time:

- `name` and `short_name` — the full name and the one that fits under a home screen icon.
- `icons` — an array of sources with sizes. 192×192 and 512×512 are the practical minimum; `purpose: "maskable"` lets Android crop the icon into its own shape without cutting off your logo.
- `start_url` — the address the app opens at, which does not have to be the page the user installed from.
- `display` — `standalone` removes the browser address bar, `browser` keeps it, `fullscreen` hides everything.
- `theme_color` and `background_color` — the system UI tint and the colour shown during launch, before the first paint.

Published NorthernGo apps are served a generated `/manifest.json` with `display: "standalone"` and a maskable icon, so the app opens from its own icon rather than inside a tab.

### Where it goes wrong

Three failure modes cover almost everything.

**Icons that look broken after install.** Android applies its own mask, so a square logo with content at the edges gets clipped. Building the icon with a safe margin, or shipping a separate maskable version, is the fix — see the [app icon guide](/resources/create-pwa-app-icons/).

**A `start_url` outside the scope.** If the start address falls outside the manifest scope, the app opens in a normal browser tab and the install looks half-broken.

**Expecting the manifest to do more than it does.** This is the common misconception: a manifest makes an app *installable*, not offline-capable and not faster. Everything about working without a connection lives in the [service worker](/glossary/service-worker/). A site with a perfect manifest and no service worker installs beautifully and then shows a blank screen on a train.

The manifest is also read at install time, so changing an icon or a name does not update apps that are already on someone's home screen until they reinstall.

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NorthernGo is an AI-powered platform for building production-ready web apps with zero coding. Local AI generation via WebGPU is unlimited and free, and you own all generated source code. https://northerngo.com/