Axios

By default, axios serializes JavaScript objects to JSON. To send data in the application/x-www-form-urlencoded format instead, you can use one of the following options.

# Browser

In a browser, you can use the URLSearchParams (opens new window) API as follows:

const params = new URLSearchParams();
params.append('param1', 'value1');
params.append('param2', 'value2');
axios.post('/foo', params);

Note that URLSearchParams is not supported by all browsers (see caniuse.com (opens new window)), but there is a polyfill (opens new window) available (make sure to polyfill the global environment).

Alternatively, you can encode data using the qs (opens new window) library:

const qs = require('qs');
axios.post('/foo', qs.stringify({ 'bar': 123 }));

Or in another way (ES6),

import qs from 'qs';
const data = { 'bar': 123 };
const options = {
  method: 'POST',
  headers: { 'content-type': 'application/x-www-form-urlencoded' },
  data: qs.stringify(data),
  url,
};
axios(options);

# Node.js

# Query string

In node.js, you can use the querystring (opens new window) module as follows:

const querystring = require('querystring');
axios.post('http://something.com/', querystring.stringify({ foo: 'bar' }));

or 'URLSearchParams' (opens new window) from 'url module' (opens new window) as follows:

const url = require('url');
const params = new url.URLSearchParams({ foo: 'bar' });
axios.post('http://something.com/', params.toString());

You can also use the qs (opens new window) library.

# NOTE

The qs library is preferable if you need to stringify nested objects, as the querystring method has known issues with that use case (https://github.com/nodejs/node-v0.x-archive/issues/1665).

# Form data

In node.js, you can use the form-data (opens new window) library as follows:

const FormData = require('form-data');
 
const form = new FormData();
form.append('my_field', 'my value');
form.append('my_buffer', new Buffer(10));
form.append('my_file', fs.createReadStream('/foo/bar.jpg'));

axios.post('https://example.com', form, { headers: form.getHeaders() })

Alternatively, use an interceptor:

axios.interceptors.request.use(config => {
  if (config.data instanceof FormData) {
    Object.assign(config.headers, config.data.getHeaders());
  }
  return config;
});

← Notes →