Creating an instance in Axios

An Axios instance keeps a baseline config, such as a base URL, a timeout and headers, so you do not repeat them on every call.

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Creating an instance in Axios: screenshot of the example below running — The code below, running in Chromium on our server (Oct 12, 2026). Press Run to see it live and change it.

How it works

Create the instance. axios.create() takes a config object. Here it sets baseURL, timeout, a custom header, and an offline adapter that reports what each request would send. [1]
Override a default for one request. The /reports call passes { timeout: 30000 }. The echoed config shows 30000 for that call and 5000 for the others. [1]
Change defaults later. After the first calls the example writes an Authorization header into api.defaults.headers.common. The next request carries it, while the global axios object keeps no baseURL. [1]

Run and edit it

It runs in your browser, in a sandboxed frame that cannot see this site; the packages load from esm.sh only after you press Run.

import axios from 'axios';

// Offline adapter: reports what the request would have sent
const echo = async (config) => ({
  data: {
    url: config.baseURL + config.url,
    timeout: config.timeout,
    custom: config.headers.get('X-Custom-Header'),
    auth: config.headers.get('Authorization') || '(none)',
  },
  status: 200,
  statusText: 'OK',
  headers: {},
  config,
});

const api = axios.create({
  baseURL: '/api/v1',
  timeout: 5000,
  headers: { 'X-Custom-Header': 'foobar' },
  adapter: echo,
});

const show = (label, { data }) =>
  console.log(label.padEnd(10), data.url, '| timeout', data.timeout, '| custom', data.custom, '| auth', data.auth);

show('users', await api.get('/users/1'));
show('reports', await api.get('/reports', { timeout: 30000 }));

// Change instance defaults after creation
api.defaults.headers.common['Authorization'] = 'Bearer demo-token';
show('me', await api.get('/me'));

console.log('instance baseURL:', api.defaults.baseURL);
console.log('global axios baseURL:', axios.defaults.baseURL);

Ctrl/⌘ + Enter runs

Each line shows the URL, timeout and headers the instance would use; try adding another default header. Code written by AgentGid [1].

Checked Oct 12, 2026: it starts without errors in Chromium with axios 1.20.0. Needs WebGL.

More Axios examples

Custom adapters in Axios Interceptors in Axios Error handling in Axios transformResponse in Axios

Sources

Docs: docs › instance

Explanations written by AgentGid from the official docs; the numbers in brackets point here. The code marked "written by AgentGid" is ours and free to copy.

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