About this tool
Review strict manifest structure and processed static evidence while keeping HTTPS, service worker, icon availability, and browser installability outside the pass claim.
- Rejects non-strict JSON, duplicate keys, unsafe integers, oversized or deeply nested data before static manifest processing.
- Resolves start_url, scope, id, icon, and shortcut URLs, then reports same-origin and navigation-scope relationships where the supplied manifest URL provides enough context.
- Separates invalid member errors from install-surface recommendations for app names, explicit identity and scope, 192/512 icon coverage, and maskable purpose.
How to use Manifest Validator
Paste manifest JSON and its source URL, validate core metadata, then review resolved start, scope, and icon URLs with explicit installability limits.
When this tool is useful
- Reviewing a web app manifest before deployment.
- Checking relative URL resolution and icon declarations.
Practical tips
- Validate the fetched icon files and service worker separately.
- Passing metadata checks does not prove browser installability.
Examples you can test
Load an example, compare the result with the expected output, then replace it with your own input.
Resolve a relative start URL
Example input
Manifest at https://example.com/app/manifest.json with start_url './home'
Expected output
Resolved https://example.com/app/home plus metadata checks
HTTPS, service worker, and browser policy remain separate.
Validation checklist
- Confirm source URL and resolved scope.
- Fetch and inspect every declared icon.
- Test installation in target browsers.