How URL encoding and decoding work

Why encode?

Links accept a limited set of English letters and symbols. Any character outside it, like a space or an Arabic letter, is written as the bytes that represent it, each byte after a % sign. An Arabic letter is two bytes in UTF-8, so it becomes six characters.

%D9%85%D8%B1%D8%AD%D8%A8%D8%A7

A whole URL or one part of it?

This difference causes most mistakes. In “Full URL” mode, the symbols that build the link, like :, /, ? and =, stay as they are, so the link still works. In “Component” mode those symbols are encoded too, which is what you need when a whole URL goes inside a value in another URL.

How to do it

1. Open the URL encoder/decoder and paste your text.
2. Choose encode or decode, then the mode: full URL or component.
3. When decoding, if there is an invalid % sequence, the tool tells you where it is instead of failing silently.
4. Copy the result.

Common mistakes

• Double encoding: encoding text that is already encoded turns % into %25. The tool warns you but does what you asked.
• Old links encoded in Windows-1256 show up as invalid UTF-8 and are not decoded.
• Full URL mode does not decode codes like %2F and %3F, because decoding them could change what the link means.

For ad campaign links, the UTM campaign link builder encodes Arabic values for you. To pick a clean page link from the start, use the URL slug generator.