Global / Window

encodeURIComponent

Encodes a URI component by replacing certain characters with UTF-8 escape sequences

Syntax

JavaScript
encodeURIComponent(uriComponent)

Parameters

ParameterTypeDescription
uriComponentstringA string to be encoded as a URI component

Return Value

A new string representing the provided string encoded as a URI component

Examples

Basic Usage
console.log(encodeURIComponent('Hello World')); // 'Hello%20World'
console.log(encodeURIComponent('a=1&b=2')); // 'a%3D1%26b%3D2'
Practical Example
function buildQuery(params: Record<string, string>) {
  return Object.entries(params)
    .map(([k, v]) => `${encodeURIComponent(k)}=${encodeURIComponent(v)}`)
    .join('&');
}
console.log(buildQuery({ q: 'hello world', page: '1' }));
Advanced Usage
const path = '/api/search?q=' + encodeURIComponent('foo bar&baz');
console.log(path); // '/api/search?q=foo%20bar%26baz'

Understanding encodeURIComponent

The encodeURIComponent method in JavaScript encodes a URI component by replacing certain characters with UTF-8 escape sequences. It belongs to the window object and is one of the most widely used methods for working with window values in modern JavaScript and TypeScript applications.

The method signature is encodeURIComponent(uriComponent). It accepts 1 parameter: uriComponent. When called, it returns a new string representing the provided string encoded as a uri component. Understanding when and how to use encodeURIComponent() helps you write more expressive, readable code.

Common use cases for encodeURIComponent include data transformation, input validation, API response processing, and building reusable utility functions. It works well alongside related methods like window-decodeuricomponent, window-encodeuri, window-decodeuri, enabling you to chain operations together for complex data manipulation pipelines.

Browser support for encodeURIComponent is excellent across all modern browsers including Chrome, Firefox, Safari, and Edge. It is also fully supported in Node.js and Deno. For older environments, transpilation with Babel or a polyfill may be needed.

Browser Compatibility

Supported in all modern browsers (Chrome, Firefox, Safari, Edge) and Node.js. Part of the ECMAScript standard.

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