Web app manifest validator

Check a web app manifest before installability surprises.

Inspect pasted manifest.json or .webmanifest content for required identity, launch, display, and icon fields in this browser tab.

* Nothing is uploaded. ManifestLens parses your file locally and never fetches icon URLs.

Choose a manifest filemanifest.json - max 5 MiB

Web app manifest validator

Make manifest metadata easier to trust

Paste a manifest.json or .webmanifest file. Keep the original file as your source backup.

ManifestLens checks the JSON object, app identity, launch fields, display mode, and icon declarations locally.

Fix blocking findings, then test the complete site in the browser because installability also depends on hosting and runtime behavior.

FAQ

What does ManifestLens check?

Does ManifestLens upload my manifest?

No. The browser reads the file with the File API and sends no source text to a server.

Does a clean result guarantee installation?

No. This tool checks common manifest fields only. Browser installability also depends on HTTPS, service worker behavior, linked manifest markup, and valid hosted assets.