There is, and it's called Sub-resource integrity: http://www.w3.org/TR/SRI/ http://www.w3.org/TR/SRI/ MaxCDN's Bootstrap CDN implements it for example: <link h

There is, and it's called Sub-resource integrity: http://www.w3.org/TR/SRI/ http://www.w3.org/TR/SRI/ MaxCDN's Bootstrap CDN implements it for example: <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstra... rel="stylesheet" integrity="sha256-7s5uDGW3AHqw6xtJmNNtr+OBRJUlgkNJEo78P4b0yRw= sha512-nNo+yCHEyn0smMxSswnf/OnX6/KwJuZTlNZBjauKhTK0c+zT+q5JOCx0UFhXQ6rJR9jg6Es8gPuD2uZcYDLqSw==" crossorigin="anonymous">