What is the MIME type of .webmanifest files?
The MIME type (media type) for Web app manifest files with the .webmanifest extension is application/manifest+json. The PWA manifest linked with <link rel="manifest">. Browsers also accept application/json.
Content-Type header
Content-Type: application/manifest+jsonText-based types should include a charset so the browser decodes characters correctly.
Server configuration
| Server | Configuration |
|---|---|
Nginx (mime.types or types {}) | application/manifest+json webmanifest; |
Apache (.htaccess) | AddType application/manifest+json .webmanifest |
IIS (web.config) | <mimeMap fileExtension=".webmanifest" mimeType="application/manifest+json" /> |
| Node.js / Express | res.type('webmanifest') or res.setHeader('Content-Type', 'application/manifest+json') |
| Amazon S3 | Set Content-Type: application/manifest+json on the object (metadata), or pass --content-type application/manifest+json to aws s3 cp |
Should .webmanifest files be compressed?
Yes. Web app manifest is text, so enabling gzip or Brotli for application/manifest+json typically saves 50–80 % of the transfer size. Make sure your server’s compression list includes this type — check with the website compression test.
Why the MIME type matters
Browsers decide what to do with a response — render, run, play or download — from the Content-Type header, not the file extension. With X-Content-Type-Options: nosniff, a wrong type causes stylesheets and scripts to be blocked outright. For uploads, never trust the type sent by the client; check the file’s content (its magic bytes) on the server.
Frequently asked questions
What is the MIME type for .webmanifest?
application/manifest+json.How do I set the Content-Type for .webmanifest in Nginx?
application/manifest+json webmanifest; is listed in the types block (usually in /etc/nginx/mime.types) and reload Nginx.