What is the correct JSON content type?

Question

I've been messing around with JSON for some time, just pushing it out as text and it hasn't hurt anybody (that I know of), but I'd like to start doing things properly.

I have seen so many purported "standards" for the JSON content type:

application/json application/x-javascript text/javascript text/x-javascript text/x-json 

But which one is correct, or best? I gather that there are security and browser support issues varying between them.

I know there's a similar question, What MIME type if JSON is being returned by a REST API?, but I'd like a slightly more targeted answer.

Answer 1

For JSON text:

application/json 

The MIME media type for JSON text is application/json. The default encoding is UTF-8. ^{(Source: RFC 4627)}

For JSONP (runnable JavaScript) with callback:

application/javascript 

Here are some blog posts that were mentioned in the relevant comments:

• Why you shouldn't use text/html for JSON
• Internet Explorer sometimes has issues with application/json
• A rather complete list of Mimetypes and what to use them for
• The official mime type list at IANA from @gnrfan's answer below

Answer 2

IANA has registered the official MIME Type for JSON as application/json.

When asked about why not text/json, Crockford seems to have said JSON is not really JavaScript nor text and also IANA was more likely to hand out application/* than text/*.

More resources:

• Media Types
• Request for Comments 4627
• bluesmoon: JSON has a type