URL Encoder Guide: Percent Encoding Explained
Published: 2026-04-20 | Category: Developer Guides
URL encoding, also called percent encoding, converts unsafe URL characters into a format that browsers and servers can transmit reliably. If your links include spaces, symbols, or non-English text, encoding helps avoid broken routes, API errors, and malformed query strings.
Why URL Encoding Matters
Some characters have special meaning in URLs. For example, ? starts a query string, & splits parameters, and # creates a fragment. If these appear inside user-provided values, they must be encoded so the server reads them as data, not control characters.
Common Examples
- Space becomes
%20 - Ampersand
&becomes%26 - Slash
/in data becomes%2F - Unicode text is UTF-8 encoded then percent-escaped
When to Encode
- Query parameter values in search/filter links
- Redirect URLs passed to OAuth/login flows
- API endpoints receiving user-generated text
- Email links with subject/body parameters
Common Mistakes
The most frequent bug is double-encoding values, such as converting %20 into %2520. Another common issue is encoding the entire URL string when only parameter values should be encoded. Always encode at the right layer: path segment, query key, or query value.
Use PKTools URL Encoder
Use our free tool to encode and decode URLs instantly, test edge cases, and verify clean query strings before deployment.