Definition

icons (manifest field)

Short definition

icons is a manifest array of objects like {"src": "/icon-512.png", "sizes": "512x512", "type": "image/png"}. Chromium requires at least a 192x192 and a 512x512 PNG for install eligibility; the browser picks the closest size for each surface (home screen, splash screen, task switcher) rather than scaling a single image.

Reviewed July 22, 2026

Supplying only one large icon works because browsers downscale, but supplying multiple explicit sizes avoids blurry results on high-density displays and lets you hand-tune small sizes for legibility.

The purpose field, e.g. "purpose": "any", "purpose": "maskable" or "purpose": "monochrome", tells the OS how the icon may be cropped or recoloured; entries without purpose default to "any".

Chromium's installability check specifically looks for a PNG (or SVG/WebP) icon of at least 192x192 with purpose "any" or unset — an icon set that only declares maskable variants can fail the check.

Test real device rendering with the Maskable.app tool, since a non-maskable icon placed inside Android's adaptive-icon mask often gets its edges clipped.

Related terms

Maskable icons

A maskable icon is declared with "purpose": "maskable" in the manifest icons array and must fill the entire square canvas with no transparent padding, keeping important content inside the central 80% "safe zone". Android then applies its own mask shape (circle, squircle, rounded square) on top without cutting off the logo.

name (manifest field)

name is a required-in-practice string field in the Web App Manifest that gives the full, human-readable title of the app. Browsers show it on the install dialog, the splash screen and in the OS app switcher. It can be up to 45 characters before some UIs truncate it.

Web App Manifest

A Web App Manifest is a JSON file (usually manifest.webmanifest) that declares your app's name, icons, start URL, theme colour and display mode. The browser reads it to render the install prompt and the home-screen icon.

shortcuts (manifest field)

shortcuts is a manifest array of up to (practically) four entries, each with name, url and optional icons, that appear when a user long-presses the installed app icon on Android or right-clicks it on Windows/ChromeOS. Example: {"name": "New order", "url": "/orders/new", "icons": [{"src": "/shortcut-new.png", "sizes": "96x96"}]}.

screenshots (manifest field)

screenshots is a manifest array such as [{"src": "/shots/home.png", "sizes": "1080x1920", "type": "image/png", "form_factor": "narrow"}] used to render a richer install UI with app previews, similar to a Play Store listing, instead of the plain one-line install banner.

id (manifest field)

id is a manifest field, for example "id": "/app-v1", used as the app's permanent identifier for the OS install registry. Unlike start_url, id is not meant to change; if it is omitted, the browser derives an identity from start_url instead, which means later changing start_url can register as a brand-new app.