URLs can only contain a limited set of characters. The rest — spaces, slashes, accented letters, emoji — must be encoded. This guide explains percent-encoding and shows how to use it.
1. What is URL encoding?
URL encoding (also called percent-encoding) replaces unsafe or reserved characters in a URL with a % followed by two hex digits. A space becomes %20, an ampersand becomes %26, and so on.
2. Which characters are encoded?
- Reserved characters like
?,#,&,=— encoded when used in a value, not a separator - Unsafe characters like spaces, quotes, brackets — must always be encoded
- Non-ASCII characters like
éor emoji — encoded as UTF-8 bytes then percent-encoded
3. How to encode URLs
Open the URL Encoder / Decoder, paste any string, and click Encode. The tool returns the percent-encoded version. Click Decode to reverse the process.
4. Common use cases
- Query parameters — values with spaces or special characters must be encoded
- Form submissions — application/x-www-form-urlencoded uses URL encoding
- API requests — most APIs accept percent-encoded strings
- Link sharing — share a URL with spaces safely by encoding first