RFC 3986 URL Percent-Encoding Encoder & Decoder

The Rules of RFC 3986 Percent-Encoding

The Uniform Resource Identifier (URI) specification defines a restricted character set permitted within URLs. Characters are categorized into unreserved characters (letters, digits, hyphen, underscore, period, tilde) which never require encoding, and reserved characters (e.g., ?, &, =, /, :, #) that act as syntactic delimiters.

When reserved characters appear within data values (such as an email address containing an '&' or '+' inside a query parameter), they must be percent-encoded as '%' followed by their two-digit hexadecimal ASCII/UTF-8 byte value to prevent web servers from misinterpreting URL boundaries.

encodeURI() vs. encodeURIComponent() — Choosing the Right Mode

In web development, selecting the wrong encoding function causes subtle routing bugs. encodeURI() encodes an entire full URL, leaving protocol separators (http://) and query delimiters (? and &) intact. In contrast, encodeURIComponent() encodes every reserved character, preparing an isolated string for safe insertion as a query parameter value.

Our tool lets you toggle between Component mode and Full URI mode, automatically highlighting encoded characters so you can inspect exact byte transformations.

Step by step: how to use URL Encoder

1. 1

   Select Encode or Decode mode depending on your current objective.

2. 2

   Choose your encoding scope: 'Component Only' (for query values) or 'Full URL' (for complete links).

3. 3

   Paste your text or encoded link into the input area.

4. 4

   View the converted string with highlighted percent-encoded tokens.

5. 5

   Click 'Copy Result' to export the clean URL ready for browser or API testing.

Frequently asked questions