URL Encoder and Decoder

How to use the URL encoder and decoder

1. Choose Encode to convert text into a URL-safe form, or Decode to turn percent-encoded text back into readable characters.
2. When encoding, pick a mode: Component for a single value (such as a query parameter or a path segment), or Full URL to encode a complete address while keeping its structure intact.
3. When decoding data that comes from an HTML form or a query string, enable Treat + as space so that + signs become spaces.
4. Paste your text and copy the result. If a percent sequence is malformed, the tool reports an error instead of guessing.

What is URL encoding?

URLs may only contain a limited set of ASCII characters. Some characters, such as /, ?, #, & and =, are reserved because they separate the parts of an address: the path, the query string and the fragment. Others, such as spaces, quotes, accented letters or emoji, are simply not allowed. URL encoding, also called percent-encoding, solves both problems by replacing each problematic byte with a % followed by two hexadecimal digits.

Text is first converted to UTF-8 bytes, and each byte is encoded separately. A space becomes %20, an ampersand becomes %26, é (two bytes in UTF-8) becomes %C3%A9, and the emoji 😀 (four bytes) becomes %F0%9F%98%80. Unreserved characters, meaning letters, digits and - _ . ~, never need encoding.

Component mode vs. full URL mode

Choosing the right mode is the most important decision, and getting it wrong is a classic source of bugs.

Component mode works like JavaScript’s encodeURIComponent. It encodes every reserved character, so the result can be safely placed inside one part of a URL. Use it for query parameter values, path segments or anything a user typed. For example, the search term rock & roll becomes rock%20%26%20roll. If you did not encode the &, the server would read roll as the start of a new parameter.

Full URL mode works like encodeURI. It assumes the input is already a complete address and preserves the characters that give it structure, such as : / ? # & and =, while encoding spaces and non-ASCII characters. Use it to clean up an address such as https://example.com/café menu?q=tea into https://example.com/caf%C3%A9%20menu?q=tea. Do not use it on individual values: an & inside a value would stay unencoded and break the query string.

A good rule of thumb: build URLs from parts, encode each value in component mode, and only use full URL mode for addresses you receive already assembled.

The + sign and form encoding

HTML forms submitted with application/x-www-form-urlencoded encode spaces as + instead of %20. That is why search URLs often look like ?q=hello+world. Standard percent-decoding leaves + unchanged, because in a path a plus is just a plus. When you decode a query string or form data, turn on Treat + as space to get hello world. Leave it off for paths and for values where a literal + matters, such as phone numbers or Base64 data. A real plus sign in form data is sent as %2B, so it is decoded correctly either way.

Privacy

Encoding and decoding run entirely in your browser. Nothing you paste, including URLs that may contain tokens, session IDs or personal data, is sent to a server or stored.