Apply percent-encoding (URL encoding) so arbitrary text is safe inside query strings, path segments, and form bodies.
Encoding rules
Unreserved characters (A–Z, a–z, 0–9, -, _, ., ~) pass through unchanged. All others — including spaces, &, =, #, ?, /, and non-ASCII Unicode — become % followed by two uppercase hex digits representing the UTF-8 byte sequence.
Spaces encode as %20 (not +, which is form-specific).
When to use it
Build ?q= search links, debug broken URLs, prepare OAuth redirect parameters, or show why raw & in a value truncates query parsing.
Limitations
application/x-www-form-urlencoded HTML forms sometimes use + for space — do not confuse the two conventions. The tool encodes full strings, not individual components already containing % escapes (double-encoding risk). Path segments may need additional slash handling per RFC 3986.
Example
For example, enter the default sample values on the form and compare the output with a known reference; adjust one input at a time to see how the result changes.