URL Encoder & Decoder
Encode or decode URL components with standard percent-encoding. Runs locally in your browser.
Encoded output will appear here.What is URL encoding?
URL encoding (percent-encoding) represents characters that aren't permitted or have special meaning in a URL using a % sign followed by two hexadecimal digits - the byte value of that character. It lets you safely include arbitrary text, including spaces, punctuation, and non-ASCII characters, inside a URL without breaking its structure.
How to use this tool
- Paste or type the text you want to encode, or a percent-encoded string you want to decode.
- Select whether you want to Encode or Decode.
- Click the action button and copy the result.
encodeURIComponent vs. encodeURI
encodeURIComponent encodes everything except unreserved characters (letters, digits, - _ . ~), which makes it the right choice for encoding a single value - a query parameter, path segment, or form field - before inserting it into a URL. encodeURI leaves URL syntax characters such as / , ? , & , and # intact, so it's meant for encoding an already-assembled, complete URL rather than a piece of one. This tool uses encodeURIComponent semantics, matching how you'd encode a value going into a query string.
Practical examples
- Encoding a search query with spaces and symbols, e.g.
coffee & tea, before appending it to?q=in a URL. - Building a redirect URL that embeds another full URL as a query parameter, e.g.
?returnTo=https%3A%2F%2Fexample.com. - Decoding a percent-encoded value copied from a browser's address bar or a server log to read it in plain text.
- Encoding a filename or path segment that contains spaces or special characters for a REST API endpoint.
Common mistakes
- Double-encoding a value that's already percent-encoded, which turns a % into %25 and produces the wrong string when decoded downstream.
- Using this tool's decode on a form-urlencoded query string that uses + for spaces - those plus signs need to be converted separately, since standard percent-decoding leaves them as literal + characters.
- Encoding an entire URL with component-style encoding, which also escapes the :// and / separators and breaks the URL.
Frequently asked questions
- Is this the same as encoding a full URL?
- No. This tool encodes URL components using encodeURIComponent, which escapes characters like /, ?, &, and # that would otherwise be treated as URL syntax. Encoding a complete URL (with encodeURI) leaves those structural characters alone so the URL still works.
- Why does a space become %20 and not +?
- Percent-encoding (RFC 3986) represents a space as %20. The + character for spaces is a convention specific to the application/x-www-form-urlencoded format used in HTML form submissions and query strings - it's a different, older encoding, not part of standard percent-encoding.
- Does a plus sign become a space on decode?
- No. This tool performs standard percent-decoding, where a literal + character decodes as +. Only form-urlencoded decoders (like the ones used for query strings) convert + back into a space.
- What causes an invalid percent-encoding error?
- Either a % character not followed by exactly two hexadecimal digits (e.g. %2 or %ZZ), or a decoded byte sequence that isn't valid UTF-8. Both indicate the input wasn't produced by a standard URL encoder.
- When should I encode a value before putting it in a URL?
- Any time the value comes from user input or contains reserved characters (spaces, &, =, ?, #, /, +, etc.) and is going into a query parameter, path segment, or form field. For inspecting or constructing multiple query parameters, use the Query String Parser & Builder. Encoding prevents the value from being misread as URL structure or breaking the request.
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