Convert all applicable characters to HTML entities

html_entity_decode
htmlspecialchars_decode
String Functions
PHP Manual

# htmlentities

(PHP 4, PHP 5)

htmlentities — Convert all applicable characters to HTML entities

### Description

string htmlentities ( string `$string` [, int `$flags` = ENT_COMPAT | ENT_HTML401 [, string `$encoding` = ini_get("default_charset") [, bool `$double_encode` = true ]]] )

This function is identical to htmlspecialchars() in all ways, except with htmlentities(), all characters which have HTML character entity equivalents are translated into these entities.

If you want to decode instead (the reverse) you can use html_entity_decode().

### Parameters

`string`

  The input string.

`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.

  Available `flags` constants
  Constant Name | Description
  --- | ---
  `ENT_COMPAT` | Will convert double-quotes and leave single-quotes alone.
  `ENT_QUOTES` | Will convert both double and single quotes.
  `ENT_NOQUOTES` | Will leave both double and single quotes unconverted.
  `ENT_IGNORE` | Silently discard invalid code unit sequences instead of returning an empty string. Using this flag is discouraged as it » may have security implications.
  `ENT_SUBSTITUTE` | Replace invalid code unit sequences with a Unicode Replacement Character U+FFFD (UTF-8) or &#FFFD; (otherwise) instead of returning an empty string.
  `ENT_DISALLOWED` | Replace 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_HTML401` | Handle code as HTML 4.01.
  `ENT_XML1` | Handle code as XML 1.
  `ENT_XHTML` | Handle code as XHTML.
  `ENT_HTML5` | Handle code as HTML 5.

`encoding`

  An optional argument defining the encoding used when converting characters.

  If omitted, the default value of the `encoding` varies depending on the PHP version in use. In PHP 5.6 and later, the default_charset configuration option is used as the default value. PHP 5.4 and 5.5 will use UTF-8 as the default. Earlier versions of PHP use ISO-8859-1.

  Although this argument is technically optional, you are highly encouraged to specify the correct value for your code if you are using PHP 5.5 or earlier, or if your default_charset configuration option may be set incorrectly for the given input.

  The following character sets are supported:

  Supported charsets
  Charset | Aliases | Description
  --- | --- | ---
  ISO-8859-1 | ISO8859-1 | Western European, Latin-1.
  ISO-8859-5 | ISO8859-5 | Little used cyrillic charset (Latin/Cyrillic).
  ISO-8859-15 | ISO8859-15 | Western European, Latin-9. Adds the Euro sign, French and Finnish letters missing in Latin-1 (ISO-8859-1).
  UTF-8 |  | ASCII compatible multi-byte 8-bit Unicode.
  cp866 | ibm866, 866 | DOS-specific Cyrillic charset.
  cp1251 | Windows-1251, win-1251, 1251 | Windows-specific Cyrillic charset.
  cp1252 | Windows-1252, 1252 | Windows specific charset for Western European.
  KOI8-R | koi8-ru, koi8r | Russian.
  BIG5 | 950 | Traditional Chinese, mainly used in Taiwan.
  GB2312 | 936 | Simplified Chinese, national standard character set.
  BIG5-HKSCS |  | Big5 with Hong Kong extensions, Traditional Chinese.
  Shift_JIS | SJIS, SJIS-win, cp932, 932 | Japanese
  EUC-JP | EUCJP, eucJP-win | Japanese
  MacRoman |  | Charset that was used by Mac OS.
  '' |  | An empty string activates detection from script encoding (Zend multibyte), default_charset and current locale (see nl_langinfo() and setlocale()), in this order. Not recommended.

  > Note: Any other character sets are not recognized. The default encoding will be used instead and a warning will be emitted.

`double_encode`

  When `double_encode` is turned off PHP will not encode existing html entities. The default is to convert everything.

### Return Values

Returns the encoded string.

If the input `string` contains an invalid code unit sequence within the given `encoding` an empty string will be returned, unless either the `ENT_IGNORE` or `ENT_SUBSTITUTE` flags are set.

### Changelog

Version | Description
--- | ---
5.6.0 | The default value for the `encoding` parameter was changed to be the value of the default_charset configuration option.
5.4.0 | The default value for the `encoding` parameter was changed to UTF-8.
5.4.0 | The constants `ENT_SUBSTITUTE`, `ENT_DISALLOWED`, `ENT_HTML401`, `ENT_XML1`, `ENT_XHTML` and `ENT_HTML5` were added.
5.3.0 | The constant `ENT_IGNORE` was added.
5.2.3 | The `double_encode` parameter was added.

### Examples

Example #1 A htmlentities() example

`<?php
$str = "A 'quote' is <b>bold</b>";
// Outputs: A 'quote' is &lt;b&gt;bold&lt;/b&gt;
echo htmlentities($str);
// Outputs: A &#039;quote&#039; is &lt;b&gt;bold&lt;/b&gt;
echo htmlentities($str, ENT_QUOTES);
?>`

Example #2 Usage of `ENT_IGNORE`

`<?php
$str = "\x8F!!!";
// Outputs an empty string
echo htmlentities($str, ENT_QUOTES, "UTF-8");
// Outputs "!!!"
echo htmlentities($str, ENT_QUOTES | ENT_IGNORE, "UTF-8");
?>`

### See Also

- html_entity_decode() - Convert all HTML entities to their applicable characters
- get_html_translation_table() - Returns the translation table used by htmlspecialchars and htmlentities
- htmlspecialchars() - Convert special characters to HTML entities
- nl2br() - Inserts HTML line breaks before all newlines in a string
- urlencode() - URL-encodes string

html_entity_decode
htmlspecialchars_decode
String Functions
PHP Manual