URL Encoder & Decoder Online Free — Encode Query Strings

URLs can only contain a limited set of ASCII characters. Special characters — spaces, ampersands, accented letters, symbols like #, ?, and = — must be percent-encoded before they can safely appear in a URL. Our free URL encoder decoder handles this translation instantly, converting any raw string into a valid percent-encoded URL component and decoding encoded strings back into readable text. Whether you're building query strings, debugging API calls, or analysing redirect chains, this tool eliminates manual encoding errors completely.

How URL Encoding Works

URL encoding (also called percent-encoding) replaces unsafe or reserved characters with a % sign followed by the two-digit hexadecimal representation of the character's ASCII code. A space becomes %20, an ampersand becomes %26, a forward slash becomes %2F, and an at-sign becomes %40. This ensures that the URL remains interpretable by any web server or browser regardless of the character set in use.

The distinction between encodeURI() (encodes the full URL, preserving reserved characters like / and ?) and encodeURIComponent() (encodes URL components, treating reserved characters as unsafe) is critical and frequently confused in web development. Our tool defaults to component-level encoding — the correct choice for encoding individual query parameter values.

Real-World Use Cases

• Search query strings: Encoding a user's search term before appending it to a Google Analytics campaign URL prevents the & in "fish & chips" from breaking the query string parameter boundary.
• OAuth redirect URIs: Many OAuth flows require the callback URL to be URL-encoded as a query parameter value — a missed encoding causes authentication failures.
• API debugging: Decoding a received webhook URL or redirect chain reveals the original path and parameters that were passed through multiple layers of encoding.
• Email marketing links: Tracking parameters appended to outbound links must be encoded to survive forwarding through various email clients and link-shortening services.

Decoding Encoded URLs for Debugging

When analysing server logs, reviewing CDN access logs, or debugging a redirect chain, URL-encoded strings appear everywhere. A raw log line like /search?q=machine%20learning%20%26%20AI is immediately readable once decoded to /search?q=machine learning & AI. Paste any encoded URL or query string into our decoder to instantly reveal every parameter name and value in plain text — dramatically accelerating debugging sessions.

Frequently Asked Questions (FAQ)