URL Encoding Explained: Percent-Encoding Made Simple
Spaces and symbols in links need special handling. This guide explains percent-encoding, when to use it, and the mistakes that break links.
What is the URL Encoder & Decoder?
Characters such as spaces, ampersands and question marks have special jobs inside a web address, so they must be percent-encoded before they can appear as data. This tool applies standard URL encoding, and reverses it on the way back. A malformed percent sequence, such as a lone percent sign, is reported as an error rather than guessed at. It encodes a single value, not a whole address with its structure intact, so do not run a complete URL through the encoder unless you expect its punctuation to be encoded too.
How to use it
- Type or paste the text to convert.
- Choose Encode or Decode.
- Press the button and copy the result.
Worked example
Encoding 'hello world & friends?' gives hello%20world%20%26%20friends%3F.
What does %20 mean in a URL?
It is the percent-encoded form of a space. Encoding replaces characters that are not safe in a URL with a percent sign followed by two hex digits.
Frequently asked questions
Should I encode a whole web address?
Usually not. Encoding a full address also encodes its slashes, colons and question marks. Encode only the individual value you are placing inside the address.
Why does decoding sometimes fail?
Decoding fails when the input contains a percent sign that is not followed by two valid hex digits. Fix the sequence and try again.