How to Encode URL Parameters — Complete Guide

URL encoding ensures your URLs are valid and consistently parsed. Use our URL Encoder / Decoder to instantly encode or decode URL components.

What is URL Encoding?

URL encoding, also known as percent encoding, replaces unsafe characters in URLs with a % sign followed by their two-digit hex code. For example, a space becomes %20, and an ampersand (&) in a parameter value becomes %26 so it is not interpreted as a parameter separator.

Common URL Encoded Characters

Character | Encoded | Reason
──────────┼─────────┼──────────────────────
Space     | %20     | Not allowed in URLs
!         | %21     | Unsafe character
"         | %22     | Unsafe character
#         | %23     | Fragment identifier
$         | %24     | Unsafe character
%         | %25     | Reserved (escape char)
&         | %26     | Query separator
'         | %27     | Unsafe character
(         | %28     | Unsafe character
)         | %29     | Unsafe character
+         | %2B     | Encodes to space in query
,         | %2C     | Unsafe character
/         | %2F     | Path separator
:         | %3A     | Scheme/port separator
;         | %3B     | Reserved character
<         | %3C     | Unsafe character
>         | %3E     | Unsafe character
?         | %3F     | Query string start
@         | %40     | Reserved character

Method 1: Encode URLs in JavaScript

Use the correct function based on what you are encoding:

// encodeURIComponent — for query parameter VALUES
const value = "hello world & more"
const encoded = encodeURIComponent(value)
// → "hello%20world%20%26%20more"

// encodeURI — for full URLs (preserves ://?#)
const url = "https://example.com/path?name=hello world"
const full = encodeURI(url)
// → "https://example.com/path?name=hello%20world"

// Manual encoding
function manualEncode(str) {
  return str.replace(/[^\w\-._~]/g, char => {
    return '%' + char.charCodeAt(0).toString(16).toUpperCase()
  })
}

Method 2: Encode URLs in Other Languages

# Python
import urllib.parse
urllib.parse.quote("hello world")  # → "hello%20world"
urllib.parse.urlencode({"q": "hello world", "page": 1})

# PHP
urlencode("hello world")   # → "hello+world"
rawurlencode("hello world")  # → "hello%20world"

# Java
import java.net.URLEncoder;
URLEncoder.encode("hello world", "UTF-8");

# Go
import "net/url"
url.QueryEscape("hello world")

Common URL Encoding Mistakes

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