OpenAnyFile
Works
Viewing, inspecting and verifying. You get a collapsible, syntax-coloured tree you can expand node by node. File details, exact byte size and the detected signature are always shown.
How to open a .webmanifest file
WEBMANIFEST files come from PWA developers, and the usual advice — buy the software that made it — is rarely what you need just to look inside one. This page covers what the format is and how to open it in a browser tab.
What is a .webmanifest file?
Web App Manifest is a data & config format developed by W3C, first appearing in 2013. It is normally produced by PWA developers.
The JSON file that makes a website installable — name, icons, theme colour and display mode all come from here.
| Full name | Web App Manifest |
|---|---|
| File category | Data & config |
| MIME type | application/manifest+json |
| Magic bytes (file signature) | 7B ({) |
| Developer | W3C |
| Introduced | 2013 |
| Usually created by | PWA developers |
| OpenAnyFile engine | JSON tree viewer |
| Opens without upload | Yes — parsed locally in your browser |
Open a .webmanifest file in your browser
OpenAnyFile routes .webmanifest to its JSON tree viewer, which parses a collapsible, syntax-coloured tree you can expand node by node.
- Open the OpenAnyFile opener in this browser — nothing to download or sign up for.
- Drag your .webmanifest file onto the drop zone, click to browse for it, or paste it with Ctrl+V.
- The extension is detected and the file is handed to the JSON tree viewer.
- Your WEBMANIFEST opens on its own viewer page: a collapsible, syntax-coloured tree you can expand node by node.
- Use fullscreen for a closer look, or download the file back out unchanged. Nothing is transmitted anywhere — the parsing happens in your own browser process.
What you can and cannot do with it here
Does not work
Editing and re-saving. OpenAnyFile is a reader, not an editor — for changes you still need special software or an equivalent.
Why your {ext} file is never uploaded
Most online viewers work by sending your file to their server, processing it there, and leaving a copy behind on infrastructure you do not control. OpenAnyFile does not. Your .webmanifest file is read through the browser's local File API and decoded by JavaScript and WebAssembly running on your own machine. There is no upload step and no server-side copy — open your browser's network tab while you do it and watch: the file never appears.
Frequently asked questions about WEBMANIFEST files
Can I open a .webmanifest file without installing special software?
Yes. OpenAnyFile's JSON tree viewer runs in your browser, so you can read a WEBMANIFEST file with nothing installed. You get a collapsible, syntax-coloured tree you can expand node by node. For full editing you still need the original application — this is a viewer, not an editor.
How can I check a file really is a WEBMANIFEST file?
Look at the first bytes rather than the extension. A genuine WEBMANIFEST begins with 7B ({). Opening the file in OpenAnyFile shows that signature in the file-details panel, so a file renamed to .webmanifest by mistake is easy to spot.
Is it safe to open a WEBMANIFEST file online?
With OpenAnyFile, yes, because nothing is uploaded. The file is read locally through your browser's File API and never leaves your device, so there is no server copy to leak, log or retain. That matters most for the kind of file people are least willing to hand to a random converter site.
What is a .webmanifest file, exactly?
Web App Manifest — an application/manifest+json format created by W3C since 2013. The JSON file that makes a website installable — name, icons, theme colour and display mode all come from here.
Does the same viewer handle formats related to WEBMANIFEST?
Yes — the same engine also opens .json, .geojson, .har, so you can compare related files without switching tools.
Related formats
These open with the same engine, so if you have one of these sitting next to your .webmanifest file, it will open too: