Every language
11 languages, copy-ready. One at a time with syntax highlighting, or all inline.
JSJavaScript
const encoded = encodeURIComponent('hello world & friends');
console.log(encoded); // hello%20world%20%26%20friends
const decoded = decodeURIComponent(encoded);
console.log(decoded); // hello world & friendsencodeURIComponent leaves A-Z a-z 0-9 - _ . ! ~ * ' ( ) intact. Its sibling encodeURI keeps URL structure (& = ? /) — usually the wrong tool for values.
TSTypeScript
const encode = (value: string): string => encodeURIComponent(value);
const decode = (value: string): string => decodeURIComponent(value);
console.log(encode('café & crème')); // caf%C3%A9%20%26%20cr%C3%A8me
console.log(decode(encode('café & crème')));decodeURIComponent throws URIError on a stray % — wrap untrusted input in try/catch.
GoGo
package main
import (
"fmt"
"net/url"
)
func main() {
encoded := url.QueryEscape("hello world & friends")
fmt.Println(encoded) // hello+world+%26+friends
decoded, _ := url.QueryUnescape(encoded)
fmt.Println(decoded)
}QueryEscape makes spaces + (query style); url.PathEscape makes them %20 for path segments. Both decode with their matching Unescape.
RsRust
use urlencoding::{decode, encode};
fn main() {
let encoded = encode("hello world & friends");
println!("{encoded}"); // hello%20world%20%26%20friends
let decoded = decode(&encoded).unwrap();
println!("{decoded}");
}Two crates split the job: urlencoding is the drop-in (%20 style, encode/decode pair), percent-encoding is the builder — utf8_percent_encode(s, NON_ALPHANUMERIC) when you need a custom ASCII set, returning a Cow<str>. decode() is Result — a stray % is an Err, not a panic.
PHPPHP
<?php
$encoded = rawurlencode('hello world & friends');
echo $encoded, PHP_EOL; // hello%20world%20%26%20friends
echo rawurldecode($encoded), PHP_EOL;rawurlencode matches %20 style. urlencode() is the form-encoding sibling that turns spaces into +.
PyPython
from urllib.parse import quote, unquote
encoded = quote('hello world & friends', safe='')
print(encoded) # hello%20world%20%26%20friends
print(unquote(encoded))quote's safe='' matters — by default '/' survives, which is wrong inside a query value. quote_plus() is the + style.
C#C#
var encoded = Uri.EscapeDataString("hello world & friends");
Console.WriteLine(encoded); // hello%20world%20%26%20friends
Console.WriteLine(Uri.UnescapeDataString(encoded));EscapeDataString is for values. EscapeUriString (obsolete in .NET 6+) kept separators — do not use it.
JvJava
import java.net.URLEncoder;
import java.net.URLDecoder;
import java.nio.charset.StandardCharsets;
public class EncodeDemo {
public static void main(String[] args) {
String encoded = URLEncoder.encode("hello world & friends", StandardCharsets.UTF_8);
System.out.println(encoded); // hello+world+%26+friends
System.out.println(URLDecoder.decode(encoded, StandardCharsets.UTF_8));
}
}URLEncoder is form-encoding: spaces become +. The pre-Java-10 overload without a charset used platform default — always pass UTF_8.
SwSwift
let queryStyle = "hello world & friends"
.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)
// "hello%20world%20&%20friends" — space escaped, & KEPT (query-structural)
let aggressive = "hello world & friends"
.addingPercentEncoding(withAllowedCharacters: .alphanumerics)
// "hello%20world%20%26%20friends"
let decoded = aggressive?.removingPercentEncodingThe CharacterSet choice decides the escaping set — .urlQueryAllowed keeps & = ? + (fine for a whole query, WRONG for one value containing &), .alphanumerics is the aggressive pick for single values. Both calls return String? because they can fail on invalid UTF-8.
KtKotlin
import java.net.URLDecoder
import java.net.URLEncoder
val encoded = URLEncoder.encode("hello world & friends", Charsets.UTF_8)
println(encoded) // hello+world+%26+friends
val decoded = URLDecoder.decode(encoded, Charsets.UTF_8)URLEncoder is FORM encoding — spaces become +, the same + vs %20 caveat as the java impl (encodeURIComponent's %20 is the other style). Always pass Charsets.UTF_8 explicitly, never rely on a platform default.
RbRuby
require 'uri'
encoded = URI.encode_www_form_component('hello world & friends')
puts encoded # hello+world+%26+friends
puts URI.decode_www_form_component(encoded)encode_www_form_component is + style (forms). ERB::Util.url_encode gives the %20 style; decode with URI.decode_uri_component.