URL Encode & Decode

Why URLs need encoding

URLs can only contain a limited set of characters. Spaces, non-English letters and symbols like &, = and % have to be written as a percent sign followed by two hexadecimal digits: a space becomes %20, & becomes %26, and é becomes %C3%A9. This is called percent-encoding or URL encoding.

Component vs whole URL

When you encode a single value, such as a search term or a redirect address that goes inside a query string, every reserved character must be encoded; this is what JavaScript's encodeURIComponent does and what the tool does by default. When you encode a complete URL, characters like :, /, ? and & must stay as they are, or the URL stops working; turn on "Whole URL" for that, which matches encodeURI.

Decoding and plus signs

In HTML form submissions, spaces are often sent as + instead of %20. The decoder treats + as a space, which is what most servers do for query strings. When you decode a full URL, its query parameters are listed in a table so you can inspect tracking links, redirect parameters or API calls at a glance.

Related tools

To embed binary data rather than text, use the Base64 encoder, and to read JSON returned by an API, use the JSON formatter. Everything runs in your browser, so private links and tokens are not uploaded.

Debugging broken links

Links break when a value containing &, #, ? or a space is inserted into a URL without encoding: the browser treats part of the value as a new parameter or as the page fragment. If a shared link opens the wrong page or loses information, decode it here to see exactly what each parameter contains. Double-encoding is another common problem, where %20 becomes %2520; decoding twice reveals it. When building links in code, always encode each parameter value separately rather than the whole string at the end.