PHP Manual: Strip HTML and PHP tags from a string

Description

string strip_tags ( string $str [, string $allowable_tags ] )

This function tries to return a string with all NULL bytes, HTML and PHP tags stripped from a given str. It uses the same tag stripping state machine as the fgetss function.

Parameters

str: The input string.
allowable_tags: You can use the optional second parameter to specify tags which should not be stripped.

Note:
HTML comments and PHP tags are also stripped. This is hardcoded and can not be changed with allowable_tags.

Note:
In PHP 5.3.4 and later, self-closing XHTML tags are ignored and only non-self-closing tags should be used in allowable_tags. For example, to allow both <br> and <br/>, you should use:

<?php strip_tags($input, '<br>'); ?>

Return Values

Returns the stripped string.

Changelog

Version	Description
5.3.4	strip_tags ignores self-closing XHTML tags in `allowable_tags`.
5.0.0	strip_tags is now binary safe.

Examples

Example #1 strip_tags example


<?php
$text = '<p>Test paragraph.</p><!-- Comment --> <a href="#fragment">Other text</a>';
echo strip_tags($text);
echo "\n";

// Allow <p> and <a>
echo strip_tags($text, '<p><a>');
?>

The above example will output:

Test paragraph. Other text
<p>Test paragraph.</p> <a href="#fragment">Other text</a>

Notes

Warning

Because strip_tags does not actually validate the HTML, partial or broken tags can result in the removal of more text/data than expected.

Warning

This function does not modify any attributes on the tags that you allow using allowable_tags, including the style and onmouseover attributes that a mischievous user may abuse when posting text that will be shown to other users.

Note:
Tag names within the input HTML that are greater than 1023 bytes in length will be treated as though they are invalid, regardless of the allowable_tags parameter.

strip_tags