Encode a parameter's name or value separately, then keep the address's structural separators in place. Encoding an entire address as though it were one value changes :, / and ? too, so it no longer functions as the same link.
URL Encoder, Decoder and Query Editor can encode a component, use form-query space encoding, decode text or replace a named query value. It reads the text locally and does not fetch the entered address.
Encode an ampersand inside a value
Suppose a search value is salt & pepper. With Encode a value for a URL, it becomes:
salt%20%26%20pepper
The assembled query is ?q=salt%20%26%20pepper. The %26 belongs to the value. A literal & between pairs instead starts another parameter.
| Character inside a value | Encoded spelling |
|---|---|
& |
%26 |
= |
%3D |
? |
%3F |
# |
%23 |
% |
%25 |
+ |
%2B |
Spaces become %20 in component mode and + in form-query mode. A literal plus needs %2B when form-style decoding is expected. The tool's Decode action treats + as a space, so it is not suitable for interpreting a literal plus in every possible URL context. The WHATWG URL Standard describes form-query parsing.
Replace one value in a working link
Paste a complete HTTP or HTTPS address, enter Parameter to change and a nonempty New parameter value, then use the main action. The editor changes every occurrence of that parameter name. It adds a missing name at the end, while other parameter pairs keep their order and original encoding. The fragment is retained.
For example, changing tag to green tea in this address:
https://example.com/search?tag=old&tag=older&sort=date#results
produces:
https://example.com/search?tag=green%20tea&tag=green%20tea&sort=date#results
This form does not use an empty replacement field to clear a parameter: both fields must be nonempty to enter edit mode. The fragment identifies a client-side location and is not sent as part of the HTTP request to the server.
Recognize double encoding
Encoding a space gives %20. Encoding that result again gives %2520, because the percent sign itself becomes %25. Decode one layer and inspect the result before deciding whether a second layer is intended. Avoid decoding the entire query before splitting its pairs, since a decoded ampersand inside a value would become ambiguous.
Unicode text is encoded as UTF-8 bytes. The precomposed é becomes %C3%A9, while an ordinary e remains unchanged. An invalid escape or incomplete encoded character is an error to fix, rather than a reason to repeatedly decode the whole address.
Test the receiving system
The component limit is 500,000 characters; the complete-address editor allows 8,000. These are tool limits, not promises that a destination accepts such long URLs.
For campaign links, UTM Builder supplies the campaign parameter names. To remove known tracking parameters, use Tracking Parameter Stripper, then test the resulting link. For any edited address, confirm the expected page and filter values in the receiving system. Do not put credentials or private personal details in a URL just because its characters are encoded.