PHP Tutorial - PHP htmlspecialchars() Function


The htmlspecialchars() function converts some predefined characters to HTML entities.

The predefined characters are:

  • & (ampersand) becomes &
  • " (double quote) becomes "
  • ' (single quote) becomes '
  • < (less than) becomes &lt;
  • > (greater than) becomes &gt;

To convert special HTML entities back to characters, use the htmlspecialchars_decode() function.


PHP htmlspecialchars() Function has the following syntax.

string htmlspecialchars ( string $string [, int $flags = ENT_COMPAT | ENT_HTML401 [, string $encoding = 'UTF-8' [, bool $double_encode = true ]]] )


  • string - The string being converted.
  • flags - A bitmask of one or more of the following flags, which specify how to handle quotes, invalid code unit sequences and the used document type. The default is ENT_COMPAT | ENT_HTML401.
  • encoding - Defines encoding used in conversion. If omitted, the default value for this argument is ISO-8859-1 in versions of PHP prior to 5.4.0, and UTF-8 from PHP 5.4.0 onwards.
  • double_encode - When double_encode is turned off PHP will not encode existing html entities, the default is to convert everything.

Available flags constants

Constant NameDescription
ENT_COMPATWill convert double-quotes and leave single-quotes alone.
ENT_QUOTESWill convert both double and single quotes.
ENT_NOQUOTESWill leave both double and single quotes unconverted.
ENT_IGNORESilently discard invalid code unit sequences instead of returning an empty string. Using this flag is discouraged as it ? may have security implications.
ENT_SUBSTITUTEReplace invalid code unit sequences with a Unicode Replacement Character U+FFFD (UTF-8) or &#FFFD; (otherwise) instead of returning an empty string.
ENT_DISALLOWEDReplace invalid code points for the given document type with a Unicode Replacement Character U+FFFD (UTF-8) or &#FFFD; (otherwise) instead of leaving them as is. This may be useful, for instance, to ensure the well-formedness of XML documents with embedded external content.
ENT_HTML401Handle code as HTML 4.01.
ENT_XML1Handle code as XML 1.
ENT_XHTMLHandle code as XHTML.
ENT_HTML5Handle code as HTML 5.

For the purposes of this function, the encodings ISO-8859-1, ISO-8859-15, UTF-8, cp866, cp1251, cp1252, and KOI8-R are effectively equivalent, provided the string itself is valid for the encoding, as the characters affected by htmlspecialchars() occupy the same positions in all of these encodings.

The following character sets are supported:

ISO-8859-1ISO8859-1Western European, Latin-1.
ISO-8859-5ISO8859-5Little used cyrillic charset (Latin/Cyrillic).
ISO-8859-15ISO8859-15Western European, Latin-9. Adds the Euro sign, French and Finnish letters missing in Latin-1 (ISO-8859-1).
UTF-8NoAliasASCII compatible multi-byte 8-bit Unicode.
cp866ibm866, 866DOS-specific Cyrillic charset.
cp1251Windows-1251, win-1251, 1251Windows-specific Cyrillic charset.
cp1252Windows-1252, 1252Windows specific charset for Western European.
KOI8-Rkoi8-ru, koi8rRussian.
BIG5950Traditional Chinese, mainly used in Taiwan.
GB2312936Simplified Chinese, national standard character set.
BIG5-HKSCSNoAliasBig5 with Hong Kong extensions, Traditional Chinese.
Shift_JISSJIS, SJIS-win, cp932, 932Japanese
EUC-JPEUCJP, eucJP-winJapanese
MacRomanNoAliasCharset that was used by Mac OS.
''NoAliasAn empty string activates detection from script encoding (Zend multibyte), default_charset and current locale (see nl_langinfo() and setlocale()), in this order. Not recommended.


PHP htmlspecialchars() Function returns the converted string.

Example 1

Convert the predefined characters "&" (less than) and ">" (greater than) to HTML entities:

$str = "This is some <b>bold</b> text.";
echo htmlspecialchars($str);

The code above generates the following result.


Convert some predefined characters to HTML entities:

$str = "PHP & 'Java'";
echo htmlspecialchars($str, ENT_COMPAT); // Will only convert double quotes
echo "<br>";
echo htmlspecialchars($str, ENT_QUOTES); // Converts double and single quotes
echo "<br>";
echo htmlspecialchars($str, ENT_NOQUOTES); // Does not convert any quotes

The code above generates the following result.