URL-Encoder

Text für sichere Verwendung in URLs kodieren. Konvertiert Sonderzeichen in prozentkodiertesFormat.

0 Zeichen

Was ist URL-Kodierung?

URL-Kodierung, auch als Prozentkodierung bekannt, ist ein Mechanismus zur Kodierung von Sonderzeichen in URLs. URLs können nur bestimmte Zeichen aus dem ASCII-Satz enthalten, daher müssen andere Zeichen in ein gültiges Format konvertiert werden.

Common Uses of URL Encoding

  • Query String Parameters: When building URLs with query parameters, encode both keys and values to prevent breaking the URL structure. For example, "search=coffee & tea" becomes "search=coffee%20%26%20tea". Without encoding, the & would be interpreted as a parameter separator, not part of the search term. This is the most common use case. Every search form, filter, or API with query parameters requires URL encoding.
  • API Endpoint Construction: REST APIs often include parameters in the URL path or query string. When calling APIs with user input, special characters, or dynamic values, encode parameters to prevent HTTP 400 errors. For example, searching for "[email protected]" in an API requires encoding the @ symbol: /api/users/user%40example.com.
  • HTML Form Submissions (GET): When HTML forms use method="GET", browsers automatically URL-encode form data before submitting. If you're building URLs manually or using JavaScript to submit forms, you must encode data yourself. Form encoding uses application/x-www-form-urlencoded format, where spaces become + (though %20 also works).
  • International Characters and Unicode: Non-ASCII characters (accented letters like é, ñ, ü, Chinese/Japanese/Korean characters, Arabic, Cyrillic, emoji) must be URL-encoded. The character is first encoded to UTF-8 bytes, then each byte becomes %XX. For example, "café" becomes "caf%C3%A9" (é = UTF-8 bytes C3 A9).
Wie funktioniert URL-Kodierung?

URL-Kodierung ersetzt unsichere ASCII-Zeichen durch ein "%" gefolgt von zwei hexadezimalen Ziffern, die den Bytewert des Zeichens darstellen. Beispielsweise wird ein Leerzeichen zu %20, wobei 20 der hexadezimale Wert für das Leerzeichen ist.

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RFC 3986 and URL Standard

Die URL-Kodierung wurde in RFC 3986 (2005) standardisiert, das die Syntax für Uniform Resource Identifier (URI) definiert. Der Standard legt fest, welche Zeichen sicher sind (A-Z, a-z, 0-9, -, _, ., ~) und welche prozentkodiert werden müssen. Vor RFC 3986 verwendeten verschiedene Systeme unterschiedliche Methoden, was zu Kompatibilitätsproblemen führte.

Security and URL Encoding

URL encoding makes data URL-safe but does not encrypt or secure it. Encoded URLs can be easily decoded. Always use HTTPS for sensitive data. Learn about encoding security

URL-Kodierung in Programmiersprachen

Jede Programmiersprache bietet Funktionen zur URL-Kodierung. Hier sind Beispiele:

// urlencode() - for form data (spaces become +)
$encoded = urlencode($data);

// rawurlencode() - RFC 3986 compliant (spaces become %20)
$encoded = rawurlencode($data);

// Building query strings
$params = http_build_query([
    'search' => 'coffee & tea',
    'category' => 'food/drink'
]);
// Result: search=coffee+%26+tea&category=food%2Fdrink

// encodeURIComponent() - for query parameters (use this!)
const encoded = encodeURIComponent('hello world & stuff');
// Result: hello%20world%20%26%20stuff

// encodeURI() - for complete URLs (rarely needed)
const fullUrl = encodeURI('https://example.com/path with spaces');

// Building URLs with parameters
const baseUrl = 'https://api.example.com/search';
const query = encodeURIComponent('[email protected]');
const url = `${baseUrl}?q=${query}`;

from urllib.parse import quote, quote_plus, urlencode

# quote() - RFC 3986 encoding
encoded = quote('hello world & stuff')
# Result: hello%20world%20%26%20stuff

# quote_plus() - form encoding (spaces become +)
encoded = quote_plus('hello world')
# Result: hello+world

# urlencode() - build query strings
params = urlencode({'search': 'coffee & tea', 'page': 1})
# Result: search=coffee+%26+tea&page=1

import (
    "net/url"
    "fmt"
)

// QueryEscape() - encode query parameter
encoded := url.QueryEscape("hello world & stuff")
// Result: hello+world+%26+stuff

// PathEscape() - encode path segments
encoded := url.PathEscape("hello/world")
// Result: hello%2Fworld

// Building URLs with parameters
u, _ := url.Parse("https://api.example.com/search")
q := u.Query()
q.Set("search", "coffee & tea")
u.RawQuery = q.Encode()

import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;

// URL encoding (always specify UTF-8)
String encoded = URLEncoder.encode("hello world & stuff",
                                   StandardCharsets.UTF_8);
// Result: hello+world+%26+stuff

// Building URLs
String baseUrl = "https://api.example.com/search?q=";
String query = URLEncoder.encode("[email protected]",
                                 StandardCharsets.UTF_8);
String fullUrl = baseUrl + query;

require 'uri'
require 'cgi'

# URI.encode_www_form_component() - standard encoding
encoded = URI.encode_www_form_component('hello world & stuff')
# Result: hello+world+%26+stuff

# CGI.escape() - alternative
encoded = CGI.escape('hello world')

# Building query strings
params = URI.encode_www_form({search: 'coffee & tea', page: 1})
# Result: search=coffee+%26+tea&page=1

using System;
using System.Web;
using System.Net;

// HttpUtility.UrlEncode() - standard encoding
string encoded = HttpUtility.UrlEncode("hello world & stuff");
// Result: hello+world+%26+stuff

// Uri.EscapeDataString() - RFC 3986 (no System.Web dependency)
string encoded = Uri.EscapeDataString("hello world & stuff");
// Result: hello%20world%20%26%20stuff

Related Tools

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Displaying text on web pages? Use our HTML Entity Encoder to safely encode HTML special characters.