URL Encode/Decode - Free Online URL Encoder Tool

What Is URL Encoding?

URL encoding, officially called percent-encoding, is the process of converting characters that have special meaning in a URL into a safe format that can be transmitted reliably over the internet. Each encoded character is replaced with a percent sign followed by two hexadecimal digits representing its ASCII value. For example, a space becomes %20, an ampersand becomes %26, and an equals sign becomes %3D.

This encoding exists because URLs follow a strict syntax defined by RFC 3986. Certain characters like ?, &, =, #, and / are reserved as delimiters that separate the scheme, host, path, query string, and fragment. When these characters appear inside a data value rather than as a delimiter, they must be encoded to prevent the URL parser from misinterpreting the structure.

PHP provides two native functions for this: urlencode() and rawurlencode(). Both convert special characters to percent-encoded form, but they differ in how they handle spaces. urlencode() replaces spaces with + signs (following the application/x-www-form-urlencoded specification used by HTML forms), while rawurlencode() replaces spaces with %20 (following RFC 3986, the standard for URL path segments). This tool uses PHP's urlencode() for encoding.

Why Is URL Encoding Needed?

Every URL on the web is a structured string with a well-defined grammar. The browser, server, and intermediate systems parse URLs by looking for specific delimiter characters. If a value in a query string or path contains one of these delimiters without encoding, the parser will interpret it as a structural element rather than data.

• Special characters break URL structure — An unencoded & inside a parameter value will be treated as a parameter separator, splitting your data across two separate parameters.
• Spaces are invalid in URLs — The HTTP specification does not allow literal spaces in URLs. A space must be encoded as %20 (RFC 3986) or + (form-encoded).
• Non-ASCII characters require encoding — Characters from other alphabets, emoji, and accented letters cannot appear raw in a URL. They must first be converted to UTF-8 bytes, then each byte is percent-encoded.
• Reserved characters have context-specific meaning — Characters like /, ?, #, :, @, and = serve as delimiters. When any of these appears inside a data value, encoding prevents ambiguity.

When Should You URL-Encode?

URL encoding is required in several common web development scenarios:

• Building query strings with user input — When a user types a search query, comment, or name that gets appended to a URL as a query parameter, every special character in that input must be encoded.
• Form submissions — HTML forms with method="GET" encode the form data into the URL automatically. Understanding this encoding helps debug form behavior.
• API request construction — When building REST API URLs programmatically, parameter values containing tokens, passwords, or user text must be encoded to preserve the URL structure.
• Redirect URLs — When passing a callback or redirect URL as a parameter, the entire URL value must be encoded so the outer URL remains valid.
• Storing URLs in databases — Encoding URLs before storage prevents injection attacks and preserves special characters during data transfer between systems.
• Email links and mailto: URIs — Query parameters in mailto links need encoding so email clients interpret the subject, body, and recipients correctly.

When Should You Decode?

URL decoding reverses the encoding process, converting percent-encoded sequences back to their original characters. You need decoding when:

• Reading API responses — URLs returned by APIs may be encoded. Decoding them makes them readable and easier to debug.
• Displaying URLs to users — Showing raw encoded URLs to end users is confusing. Decode them for a human-friendly display.
• Extracting parameter values — When parsing a URL to read specific query parameter values, the values will be percent-encoded and need decoding.
• Debugging URL issues — Decoding reveals the actual content of a URL so you can identify encoding problems or double-encoding bugs.

Characters That Do Not Need Encoding

Not every character in a URL requires encoding. RFC 3986 defines unreserved characters that are always safe to use without percent-encoding:

• Letters — A-Z and a-z are always safe.
• Digits — 0-9 are always safe.
• Hyphen — - is always safe.
• Underscore — _ is always safe.
• Period — . is always safe.
• Tilde — ~ is always safe.

Everything else — spaces, angle brackets, curly braces, pipes, backslashes, double quotes, ampersands in values, equals signs in values, plus signs in values, and any non-ASCII characters — should be encoded.

URL Encoding vs HTML Encoding

These two encoding schemes serve different purposes and are frequently confused:

• URL encoding (percent-encoding) uses %XX notation for URLs. A space becomes %20. It is used in URLs, query strings, and HTTP headers.
• HTML encoding uses named entities for display in HTML. A space becomes  , a less-than becomes <. It is used inside HTML documents to safely display special characters.

Never mix the two. A URL parameter value that contains < is HTML-encoded, not URL-encoded. If you paste it into a URL, the browser will not interpret it correctly.

Common Use Cases in Web Development

• Search functionality — When a user searches for "hello world", the query string becomes ?q=hello+world or ?q=hello%20world depending on the encoding method.
• Social media sharing links — Pre-filled tweet and post URLs encode the message text, hashtags, and URLs in the body using percent-encoding.
• Payment gateway parameters — Payment processors require callback URLs, order descriptions, and customer data to be properly encoded in the request.
• OAuth and authentication flows — Authorization codes, access tokens, and redirect URIs must be encoded per the OAuth 2.0 specification.
• Email marketing links — UTM parameters and tracking codes in email links must be encoded to survive email client processing.
• JavaScript fetch and XMLHttpRequest — When building URLs in JavaScript for AJAX calls, parameter values must be encoded. Modern browsers provide encodeURIComponent() for this purpose.

How to Use This Tool

1. Enter your URL or text — Paste or type the URL, query string, or text containing special characters into the input area.
2. Click Encode — The tool encodes special characters to percent-encoded format using PHP's urlencode().
3. Copy or Download — Use the Copy button to copy the result to your clipboard, or click Download as TXT to save it as a file.

Need to decode instead? The tool also supports URL Decode mode to reverse percent-encoded strings back to their original readable form.

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Privacy and Security

URL encoding is performed entirely on our servers using PHP's native urlencode() function. We do not store your input or encoded output. The tool processes your data in memory and discards it immediately after returning the result. No cookies, tracking scripts, or analytics collect your encoded URLs.