URL Encoder / Decoder

How to use this tool

1. Choose a mode. Select Component to encode individual values, Full URL to encode a complete URL while preserving its structure, or Decode to percent-decode an encoded string. In Component mode, choose Standard, Strict, Form, or Path-aware to match the target format.
2. Enter your text. Type or paste the text to encode or decode into the input area. Output updates instantly.
3. Toggle + as space (decode mode). If you are decoding a form-encoded query string where spaces were encoded as +, enable "Treat + as space". Leave it off for path segments or other non-form-encoded strings.
4. Copy the result. Use the Copy button to copy the encoded or decoded output to your clipboard.

What is URL encoding?

URL encoding (also called percent-encoding) is a mechanism for representing characters that are not permitted in a URL, or that have a special meaning within a URL, as a safe sequence of ASCII characters. Each unsafe character is replaced by a percent sign (%) followed by two hexadecimal digits representing the byte value of the character in UTF-8. For example, a space becomes %20, an ampersand becomes %26, and an emoji like 🌍 becomes %F0%9F%8C%8D.

Component vs Full URL encoding

Component encoding (encodeURIComponent)

encodeURIComponent is the most aggressive encoder. It encodes every character except letters (A–Z, a–z), digits (0–9), and a small set of unreserved punctuation (- _ . ! ~ * ' ( )). This includes the characters that give a URL its structure: :, /, ?, #, &, and =: all get encoded.

Use Component mode when encoding an individual query parameter name or value. For example, if the value is rock & roll, encoding it as a component gives rock%20%26%20roll, which is safe to embed in a URL as ?genre=rock%20%26%20roll.

Component mode also offers three formats for specific contexts. Strict additionally escapes !'()*, which can help when a signer requires strict RFC 3986 encoding. Form follows application/x-www-form-urlencoded rules, including writing spaces as +. Path-aware encodes each slash-separated path segment but preserves the / separators. Choose the format expected by the system that will read the value; these outputs are not interchangeable in every context.

Full URL encoding (encodeURI)

encodeURI is less aggressive. It preserves all characters that have structural meaning in a URL (; , / ? : @ & = + $ # in addition to unreserved chars), so the URL remains valid and navigable after encoding. Only characters that are genuinely invalid in a URL get percent-encoded.

Use Full URL mode when encoding a complete URL. For example, https://example.com/path to file?q=hello world becomes https://example.com/path%20to%20file?q=hello%20world: the protocol, slashes, and query separator are left intact.

Decoding percent-encoded strings

Switch to Decode mode to reverse percent-encoding. Paste any percent-encoded URL, query string, or path segment and the tool will decode all %XX sequences back to their original characters.

Enable the Treat + as space toggle when decoding form-encoded query strings (the application/x-www-form-urlencoded format used by HTML forms). In this format, spaces are encoded as + rather than %20. Most URLs from web applications use %20 for spaces, so leave the toggle off unless you know your input is form-encoded.

Common use cases

• Building query strings: encode each parameter value with Component mode before assembling ?key=value&key2=value2.
• Sharing URLs with spaces or special characters: encode the full URL so it can be safely pasted into a message, email, or document.
• Debugging encoded URLs: paste an opaque encoded URL into Decode mode to read the original parameter values.
• Form submissions: decode form data that uses + for spaces by enabling the Treat + as space toggle.
• JWT and OAuth payloads: URL-encoded strings appear in many OAuth redirect URIs and token endpoints; decode them here to inspect the values.

RFC 3986 character categories

Form data encoding (‘+’ vs ‘%20’)

HTML form submissions using the application/x-www-form-urlencoded content type encode spaces as + rather than %20. This diverges from RFC 3986 and is a common source of bugs when developers mix the two encoding systems. When building query strings manually in JavaScript, encodeURIComponent produces %20 for spaces; when using URLSearchParams, spaces become +. Know which convention your server-side code expects.

Double-encoding pitfall

Encoding an already-encoded string turns %20 into %2520 (‘%’ itself is encoded as %25). This is a very common mistake when a URL passes through multiple encoding layers. Detect it by looking for %25 in the encoded output - if present, the input was already partially encoded. To avoid it, always decode fully first, then re-encode from the decoded form.