Body.json()

The json() method of the Body mixin takes a Response stream and reads it to completion. It returns a promise that resolves with the result of parsing the body text as JSON.

Syntax

response.json().then(function(data) {
  // do something with your data
});

Parameters

None.

Returns

A promise that resolves with the result of parsing the body text as JSON. This could be anything that can be represented by JSON — an object, an array, a string, a number...

Example

In our fetch json example (run fetch json live), we create a new request using the Request.Request constructor, then use it to fetch a .json file. When the fetch is successful, we read and parse the data using json(), then read values out of the resulting objects as you'd expect and insert them into list items to display our product data.

var myList = document.querySelector('ul');
var myRequest = new Request('products.json');
fetch(myRequest)
  .then(function(response) { return response.json(); })
  .then(function(data) {
    for (var i = 0; i < data.products.length; i++) {
      var listItem = document.createElement('li');
      listItem.innerHTML = '<strong>' + data.products[i].Name + '</strong> can be found in ' +
                           data.products[i].Location +
                           '. Cost: <strong>£' + data.products[i].Price + '</strong>';
      myList.appendChild(listItem);
    }
  });

Specifications

Browser compatibility

[1] Behind a preference in version 41.

[2] Behind a preference starting with version 34.

[3] Behind a preference in version 28.

See also

• ServiceWorker API
• HTTP access control (CORS)
• HTTP