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URL Encoder / Decoder

Encode or decode URLs and query strings using encodeURIComponent. See exactly which characters were encoded and why.

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What is URL Encoder / Decoder?

URL encoding (percent-encoding) converts characters that are not allowed in URLs into a % followed by two hexadecimal digits. This tool encodes and decodes URL components using the encodeURIComponent standard, which is safe for query string values and path segments.

How to use

  1. 1 Type or paste text into the left textarea.
  2. 2 Click 'Encode →' to percent-encode special characters.
  3. 3 To decode, paste an encoded URL into the right textarea and click '← Decode'.
  4. 4 The encoded characters panel shows which specific characters were transformed.
  5. 5 All processing is done locally in your browser.

Formula

encodeURIComponent() encodes all characters except: A–Z a–z 0–9 - _ . ! ~ * ' ( ). All other characters become %XX where XX is the UTF-8 hex byte value.

Example calculation

The string 'hello world & more=fun' encodes to 'hello%20world%20%26%20more%3Dfun'. Spaces become %20, & becomes %26, = becomes %3D.

Frequently asked questions

What is the difference between encodeURI and encodeURIComponent?

encodeURI encodes a full URL and leaves characters like /, ?, #, & intact. encodeURIComponent encodes everything except unreserved characters — use it for individual query parameter values.

Why does space become %20 and not +?

Both %20 and + represent spaces in URLs, but they are used in different contexts. %20 is standard (RFC 3986). The + sign is used in application/x-www-form-urlencoded encoding (HTML forms).

What characters don't need encoding?

Unreserved characters never need encoding: letters (A-Z, a-z), digits (0-9), and the symbols - _ . ~ These are safe in any URL context.

What is %20?

%20 is the percent-encoded representation of a space character. The hex value of ASCII space (32) is 20, so it encodes as %20.

Can I use this to decode a full URL?

Use the decode direction to decode individual components. Decoding a full URL with encoded path segments or query strings works fine with this tool.