%28 is the URL-encoded left parenthesis (().
In a URL, %28 stands for the left parenthesis ((). Here is when to encode it, what it does in each part of a URL, and what every major language outputs.
Quick facts
| Character | ( |
|---|---|
| Name | Left parenthesis |
| Unicode | U+0028 |
| UTF-8 bytes | 28 (1 byte) |
| Percent-encoded | %28 |
| Lowercase form | %28 — identical meaning |
| Double-encoded | %2528 |
| HTML form encoding | %28 |
| RFC 3986 class | Reserved — sub-delimiter |
What it means in a URL
Parentheses are sub-delimiters and may appear raw. encodeURIComponent and Java keep them; most other encoders produce %28. Markdown is the usual place they cause trouble.
RFC 3986 class: Reserved — sub-delimiter. RFC 3986 allows it raw in paths and queries, but some schemes and servers give it meaning, so encoding it as data is the safe choice.
When to encode it
| Where it appears | What to do |
|---|---|
| Path segment | Allowed raw (encoding is also fine) |
| Query value | Allowed raw (encoding is also fine) |
| Fragment | Allowed raw |
| Form body | Encode |
The mistake to watch for
Markdown links: [text](https://en.wikipedia.org/wiki/Go_(game)) ends at the first ). Encode the parentheses as %28/%29 in Markdown.
What each language produces
Left as-is by JavaScript encodeURIComponent(s), JavaScript encodeURI(s); every other function in the table encodes it. Output for the single character, UTF-8 input, tested against the real runtimes (see the encoding comparator for your own strings).
| Function | Output | |
|---|---|---|
| JavaScript encodeURIComponent(s) | ( | kept |
| JavaScript encodeURI(s) | ( | kept |
| JavaScript URLSearchParams | %28 | encoded |
| Python urllib.parse.quote(s) | %28 | encoded |
| Python quote(s, safe="") | %28 | encoded |
| Python urllib.parse.quote_plus(s) | %28 | encoded |
| PHP rawurlencode($s) | %28 | encoded |
| PHP urlencode($s) | %28 | encoded |
| Java URLEncoder.encode(s, UTF_8) | %28 | encoded |
| Go url.QueryEscape(s) | %28 | encoded |
| Go url.PathEscape(s) | %28 | encoded |
| Ruby URI.encode_www_form_component(s) | %28 | encoded |
| Ruby ERB::Util.url_encode(s) | %28 | encoded |
| C# / .NET Uri.EscapeDataString(s) | %28 | encoded |
Decoding it
decodeURIComponent('%28') returns the left parenthesis ((). Python: urllib.parse.unquote('%28'); PHP: rawurldecode('%28'). Paste any string into the URL decoder to decode it in your browser.
← %27 Apostrophe (single quote) · Full URL encoding table · %29 Right parenthesis →
Common questions.
%28 is the percent-encoded form of the left parenthesis ((), whose byte value is 0x28. Decoding the URL turns it back into the character.
Yes. Hex digits in percent-encoding are case-insensitive, so %28 and %28 mean the same thing. RFC 3986 recommends uppercase, and mixing cases can make caches and analytics count one URL as two.
Use your language’s encoder on the value: encodeURIComponent in JavaScript gives (, Python’s quote(s, safe="") gives %28, PHP’s rawurlencode gives %28.
More from the toolkit.
About this page. Written and maintained by Sri Murugan Systems, the developer of urlencodedecode.com. Character classes follow RFC 3986 §2; language outputs were generated by running each function in its real runtime.