URL Encoder

A URL can only contain a restricted set of characters. Everything else — spaces, accents, ampersands, anything non-Latin — has to be written as a percent escape, so a space becomes <code>%20</code> and an ampersand becomes <code>%26</code>.

The part that catches people out is that there are two different encodings, and choosing the wrong one produces a bug rather than an error. Encoding a whole address must leave the characters that give it structure alone — the colon, the slashes, the question mark, the ampersands between parameters — or it stops being an address. Encoding a single value inside that address must escape exactly those characters, or a value containing an ampersand splits into two parameters and quietly corrupts whatever receives it.

Both are offered here as a plain choice, with what each one does spelled out, rather than a single button that is right half the time. If you are encoding something to put after an <code>=</code> in a query string, you want the one that escapes everything.

Anything can be encoded, including emoji and non-Latin text, which become several escapes each because the encoding works on UTF-8 bytes rather than characters. That is why one Hindi or Japanese character turns into three percent escapes.

It runs in your browser. URLs regularly carry access tokens, session identifiers and email addresses, so nothing typed here is transmitted or logged.