URL

`URL.prototype.port`

Returns or sets the port number of the URL as a string

Syntax

JavaScript

url.port

Return Value

A string containing the port number, or empty string for default ports

Examples

Basic Usage

const url = new URL('https://example.com:8080/path')
console.log(url.port) // '8080'

Practical Example

const url = new URL('https://example.com/path')
console.log(url.port) // '' (default port 443)

Advanced Usage

const url = new URL('http://localhost:3000')
url.port = '8080'
console.log(url.href) // 'http://localhost:8080/'

Understanding URL.prototype.port

The URL.prototype.port method in JavaScript returns or sets the port number of the URL as a string. It belongs to the URL object and is one of the most widely used methods for working with url values in modern JavaScript and TypeScript applications.

The method signature is url.port. When called, it returns a string containing the port number, or empty string for default ports. Understanding when and how to use port() helps you write more expressive, readable code.

Common use cases for URL.prototype.port include data transformation, input validation, API response processing, and building reusable utility functions. It works well alongside related methods like url-hostname, url-host, url-origin, enabling you to chain operations together for complex data manipulation pipelines.

Browser support for URL.prototype.port 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.