Encode the five markup characters, or decode the entities you paste. Nothing is sent to a server.
1
1
An HTML character reference stands in for a character that would otherwise be markup or awkward to type. Encoding here always rewrites & < > " and ' as & < > " and '.
Decoding reads those names, a short list of other common names, and numeric references in decimal (é) or hex (é). A name this page does not know is left as it was written. The semicolon is required.
a < b & c
a < b & c
é
é
&foo; stays &foo; because that name is not in the list this page decodes. The HTML specification has a much longer catalog. Use a numeric reference when the name is missing here.
A reference without a semicolon is not decoded. é stays text. Names are case-sensitive: < is decoded, and so are the uppercase aliases < > & and ".
Encoding text that already contains < escapes the ampersand, so the result is &lt;. Decode first if that was not what you wanted.
Besides the five markup characters, decoding knows nbsp, copy, reg, trade, euro, pound, yen, cent, sect, para, middot, bull, hellip, ndash, mdash, the curly quotes, laquo, raquo, times, divide, deg, plusmn, micro, not and shy.
Numeric references that land on a surrogate code point, or past U+10FFFF, are left unchanged. The page does not parse tags: it only rewrites character references.
Each side is limited to 100,000 characters. The share link stores the source side and the numeric switch. The other side is computed again when the link is opened.
' is the XML name for an apostrophe, and HTML5 defines it too. The HTML 4.01 entity list did not include it. A numeric ' has been safe for longer.
is U+00A0, the no-break space. It looks like a space and it counts as a different character, which is why a trimmed line can still look padded.