Converting HTML to plain text in PHP for e-mail

There's the trusty strip_tags function. It's not pretty though. It'll only sanitize. You could combine it with a string replace to get your fancy underscores.

<?php
// to strip all tags and wrap italics with underscore
strip_tags(str_replace(array("<i>", "</i>"), array("_", "_"), $text));

// to preserve anchors...
str_replace("|a", "<a", strip_tags(str_replace("<a", "|a", $text)));

?>

Use html2text (example HTML to text), licensed under the Eclipse Public License. It uses PHP's DOM methods to load from HTML, and then iterates over the resulting DOM to extract plain text. Usage:

// when installed using the Composer package
$text = Html2Text\Html2Text::convert($html);

// usage when installed using html2text.php
require('html2text.php');
$text = convert_html_to_text($html);

Although incomplete, it is open source and contributions are welcome.

Issues with other conversion scripts:

• Since html2text (GPL) is not EPL-compatible.
• lkessler's link (attribution) is incompatible with most open source licenses.

here is another solution:

$cleaner_input = strip_tags($text);

For other variations of sanitization functions, see:

https://github.com/ttodua/useful-php-scripts/blob/master/filter-php-variable-sanitize.php