- PHP Manual
- String Functions
- Strip HTML and PHP tags from a string
strip_tags
(PHP 4, PHP 5, PHP 7, PHP 8)
strip_tags — Strip HTML and PHP tags from a string
Description
$string, array|string|null $allowed_tags = null): string
This function tries to return a string with all NULL bytes, HTML and PHP tags stripped
from a given string. It uses the same tag stripping
state machine as the fgetss() function.
Parameters
-
string -
The input string.
-
allowed_tags -
You can use the optional second parameter to specify tags which should not be stripped. These are either given as string, or as of PHP 7.4.0, as array. Refer to the example below regarding the format of this parameter.
Note:
HTML comments and PHP tags are also stripped. This is hardcoded and can not be changed with
allowed_tags.Note:
Self-closing XHTML tags are ignored and only non-self-closing tags should be used in
allowed_tags. For example, to allow both<br>and<br/>, you should use:<?php
strip_tags($input, '<br>');
?>
Return Values
Returns the stripped string.
Changelog
| Version | Description |
|---|---|
| 8.0.0 |
allowed_tags is nullable now.
|
| 7.4.0 |
The allowed_tags now alternatively accepts an array.
|
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($text, '<p><a>');
// as of PHP 7.4.0 the line above can be written as:
// echo strip_tags($text, ['p', 'a']);
?>
The above example will output:
Test paragraph. Other text <p>Test paragraph.</p> <a href="#fragment">Other text</a>
Notes
This function should not be used to try to prevent XSS attacks. Use more appropriate functions like htmlspecialchars() or other means depending on the context of the output.
Because strip_tags() does not actually validate the HTML, partial or broken tags can result in the removal of more text/data than expected.
This function does not modify any attributes on the tags that you allow
using allowed_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
allowed_tagsparameter.
