Definition and Usage

The encodeURI() function encodes an entire URL, except for special characters that are used to define its structure.

It is primarily used to encode entire URL strings.

Features

  • Special characters with specific meanings in a URL, such as protocol, domain, and path delimiters (/, :, ?, &, #), are not encoded.
  • Therefore, this function is suitable when the URL structure needs to be preserved.
  • It is appropriate for encoding an entire URL,
  • but not suitable for encoding individual URL components such as protocol, domain, path, or query values. In such cases, the encodeURIComponent() function should be used.

Note:
The encodeURI() function is designed to encode a full URL while preserving its structure, leaving characters like /, :, ?, &, and # intact. However, encoding individual URL components that contain these characters can cause issues. For example, if a path segment includes an &, it might be mistaken for a query separator. In such cases, the encodeURIComponent() function, which performs thorough encoding, should be used.

Basic Example

JavaScript 
const uri = "https://www.example.com/?x=Sample Value";
const encoded = encodeURI(uri);

console.log(encoded);
// Output: "https://www.example.com/?x=Sample%20Value"

The encodeURI() function has the following syntax:

Syntax

JavaScript 
encodeURI(uri);

Parameters

Parameters of the encodeURI() function
uri The complete URL to encode. This function encodes the URL except for certain special characters within its components.

Return value

Returns a new string representing the encoded URI.

Characters Not Encoded by encodeURI()

  • Alphabetic characters (A–Z, a–z)
  • Digits (0–9)
  • ;
  • ,
  • /
  • ?
  • :
  • @
  • &
  • =
  • +
  • $
  • -
  • _
  • .
  • !
  • ~
  • *
  • '
  • (
  • )
  • #

Any other characters not listed here (including spaces) are encoded as a percent sign (%) followed by the character's Unicode value in hexadecimal.

Example

JavaScript 
const uri = "https://example.com/search?query=Hello, world!&page=1";
const encodedUri = encodeURI(uri);

console.log(encodedUri);
// Output: "https://example.com/search?query=Hello,%20world!&page=1"

In this example, the encodeURI() function encodes the URI stored in the uri variable. Characters that are not encoded include :, /, ?, &, =, and !.

Important Note

Using encodeURI() alone cannot form valid HTTP GET or POST requests, such as those made with XMLHttpRequest. This is because characters like &, +, and = are not encoded and can be interpreted as special characters in GET and POST requests. In contrast, the encodeURIComponent() function encodes these characters.

Specifications

Specification for JavaScript encodeURI() Function
Specification
encodeURI() ECMAScript Language Specification
#sec-encodeuri-uri

Browser compatibility

Browser compatibility for JavaScript encodeURI() Function
Function
Desktop Chrome
Chrome
DesktopDesktop Edge
Edge
Desktop Firefox
Firefox
Safari
Safari
encodeURI() 1 12 1 1.1

See also