How to escape strange characters from text field input?

It’s a must practice to sanitize all data from user input before insert to database.

To escape unwanted characters, use the core WordPress core function sanitize_text_field():

$title = sanitize_text_field( $_POST['title'] );
update_post_meta( $post->ID, 'title', $title );

Behind the scenes, sanitize_text_field() does the following:

• Checks for invalid UTF-8
• Converts single less-than characters (<) to entity
• Strips all tags
• Removes line breaks, tabs and extra white space
• Strips octets