URL Encoder/Decoder

Making special characters safe for a URL, and reading them back

URLs can only carry a limited set of characters. Spaces, accented letters, ampersands and slashes inside a value have to be written as percent codes, or they break the address or change its meaning. This page does that conversion in both directions. Encode applies the browser's built-in encodeURIComponent function, and Decode applies decodeURIComponent. There is nothing to install, and the text stays on your computer.

Step by step

1. Type or paste the text into the top box, labeled Input.
2. Press Encode to convert it to percent codes, or Decode to convert percent codes back to plain characters.
3. Read the converted text in the Output box underneath. It cannot be edited directly.
4. Press Copy to take the result with you.

What to watch for

Encoding here is the strict, component-level kind. Colons, slashes, question marks, equals signs and ampersands are all converted, so running a complete URL through it yields a string that is no longer clickable. Use it on one piece at a time: a search term, a UTM campaign name, or a whole URL that has to ride inside another URL's query string. A space is written as %20, not as the plus sign that HTML forms use.

On the decoding side, the plus sign is left alone, so form-style query strings keep their plus signs where spaces used to be. Malformed input, such as a percent sign not followed by two hex digits, stops the conversion and shows an error alert. Each press of Decode removes one layer, so a value encoded twice needs two rounds; move the output back into the Input box between them.

Questions people ask

Should my page URLs contain encoded characters?

For English-language sites, plain lowercase letters, numbers and hyphens avoid the question entirely. For other languages, Google's URL structure guidelines say to use UTF-8 encoding where needed, so percent codes in a slug written in another language are normal.

Why does my decoded text still have plus signs in it?

Web forms often send spaces as plus signs, but the decoder follows the rules for URL components, where plus is an ordinary character. Swap the plus signs for spaces before you decode, so any genuine encoded plus (%2B) survives.

Is this safe for URLs that contain tokens or personal data?

The conversion runs entirely in the page with no network request, so the text is not transmitted. Still, clear the boxes when you finish on a shared computer.

Further reading: UTM Parameters and URL Structure FAQ: Best Practices for SEO-Friendly URLs.

The same tool is also published on the static mirror at seoprocheck.github.io, and the rest of the set is on the free tools page.