Why is my site.webmanifest not working?

The usual causes, in order: the tag is missing or on only some pages; the href returns a 404 or your SPA's index.html instead of JSON; the JSON has a syntax error such as a trailing comma; icons are missing, not 192 and 512 pixels, or their src paths 404 because they are resolved relative to the manifest URL rather than the page; display is set to browser; or start_url is missing or outside scope. This validator checks each of those for a live URL.

To the manifest file, usually at the site root: . Use a root-absolute path so it resolves correctly from every page, and include the tag in the of every page, not just the home page. If your manifest is on another origin you also need crossorigin="use-credentials" when it requires cookies.

Does the manifest need the application/manifest+json MIME type?

Chrome and Safari parse the manifest even when it is served as application/json or text/plain, but the spec type is application/manifest+json and some tooling checks for it. Serving HTML (text/html) is a real error: it means the path is falling through to a page.

Why does Chrome not show the install prompt?

Chrome requires: HTTPS, a manifest with name or short_name, a start_url, display set to standalone, fullscreen or minimal-ui, and icons of at least 192x192 and 512x512 in PNG, SVG or WebP. Missing any of these blocks the prompt. A registered service worker used to be required and is still recommended.

Does this validator store my manifest or URL?

No. URL checks are fetched once by our server, returned to your browser and discarded; pasted JSON never leaves your browser. The lint rules themselves run client-side.

Web Manifest Validator — why isn't my `site.webmanifest` working?

Enter your site URL. We fetch the page, find the <link rel="manifest"> tag, load the manifest, check its status and MIME type, HEAD-check every icon, and lint the JSON against the spec and Chrome's install criteria — every finding comes with the fix. Or paste the JSON if the site is local. Fix it in the generator with one click.

1 · Source icon one image → every size

Drop, paste or click to upload your app icon

Square PNG or SVG, 512px+ recommended · transparent background is fine · never leaves your browser

No logo yet? Start with a letter:

Letter

Background

Letter color

2 · App identity

Name (full)

Short name (≤12, under the icon)

Description

start_url

scope

display

orientation

lang

theme_color

background_color

Icon background (iOS/maskable)

3 · What to generate 192 + 512 PWA icons are always included

Maskable icons 192 + 512Android adaptive icons — padded so the launcher mask never clips your logo Apple touch icon 180×180iOS home screen; opaque, square corners (iOS rounds them) favicon.ico + 16/32/48 PNGBrowser tabs and bookmarks Monochrome icon 512Android 13+ themed icons: white silhouette of your logo Windows tile 150 + browserconfig.xmlPinned sites in Edge / Start menu iOS splash screens (9 sizes)apple-touch-startup-image PNGs for current iPhones and iPads — adds ~1–3 MB

Maskable safe-zone padding: 20%

Preview maskable under Android masks, then each platform

Safe zone

Circle

Squircle

Rounded

Tab 16

iOS 180

Android 192

Monochrome

Splash

site.webmanifest validated live

Paste into <head>

Download the kit

Unzip into your site root (next to index.html), paste the snippet into <head>, deploy. Then switch to Validate above and enter your URL to confirm every file is reachable.

Check a live site we fetch the page, find `<link rel="manifest">`, load the manifest and HEAD-check every icon

Site URL or manifest URL

Works for any public site. Nothing is stored. If your site is on localhost, paste the JSON below instead.

…or paste manifest JSON

site.webmanifest / manifest.json

Results errors block installation; warnings degrade it

Enter a URL or paste JSON to see what browsers will complain about — each finding comes with the fix.

Web Manifest Validator — why isn't my site.webmanifest working?