mime_types_handler

The "mime_types_handler" manifest key registers your extension as a handler for supported MIME types, such as application/pdf. When a user opens a document of a registered MIME type, Chrome loads your handler page in place of its built-in viewer.

For more information and examples, see the chrome.mimeHandler API documentation.

{
  // ...
  "mime_types_handler": {
    "application/pdf": {
      "handler_url": "viewer.html",
      "can_embed": true
    }
  },
  // ...
}

"mime_types_handler" (dictionary, optional)

Maps MIME types to the extension pages that render them. As of Chrome 151, application/pdf is the only MIME type available to public handlers. Declaring an unsupported MIME type causes an installation warning.

"handler_url" (string, required)

The HTML file to display when a document of the corresponding MIME type is opened. This file must be located within your extension.

"can_embed" (boolean, optional)

Specifies whether to handle documents embedded in <embed>, <object>, or <iframe> elements. Defaults to false, meaning the handler only receives top-level navigations.