URL Encode/Decode

What is a URL

A URL (Uniform Resource Locator) is a string used to locate internet resources, consisting of protocol, domain name, path, etc. Since URLs can only contain the ASCII character set, special characters and non-ASCII characters must be encoded.

What is URL Encoding

URL encoding (percent-encoding) converts special characters to a % followed by two hexadecimal digits. This ensures safe data transmission in URLs by preventing ambiguity with special characters. For example, spaces are encoded as %20 or +.

Python Implementation

      
from urllib.parse import quote, unquote

# Encoding
encoded = quote("hello world!@", safe="")
print(encoded)  # hello%20world%21%40

# Decoding
decoded = unquote("hello%20world%21%40")
print(decoded)  # hello world!@
      
    

JavaScript Implementation

      
// Encoding
const encoded = encodeURIComponent('hello world!@');
console.log(encoded); // hello%20world%21%40

// Decoding
const decoded = decodeURIComponent('hello%20world%21%40');
console.log(decoded); // hello world!@
      
    

Java Implementation

      
import java.net.URLEncoder;
import java.net.URLDecoder;

// Encoding
String encoded = URLEncoder.encode("hello world!@", "UTF-8");
System.out.println(encoded); // hello+world%21%40

// Decoding
String decoded = URLDecoder.decode("hello+world%21%40", "UTF-8");
System.out.println(decoded); // hello world!@