Using WordPress ‘pre_user_{$field}’ PHP filter

‘pre_user_{$field} is a dynamic WordPress PHP filter a that allows you to modify the value of a user field in the ‘db’ context before it’s saved to the database.

This filter uses a dynamic hook name, which means you can apply it to various user fields, such as ‘user_login’, ‘user_email’, ‘first_name’, and so on.


function my_pre_user_field( $value ) {
    return 'John';
add_filters( "pre_user_{$field}", "my_pre_user_field" );


  • $field: string (dynamic part of the hook name representing the prefixed user field being filtered)
  • $value: mixed (the value of the prefixed user field)


Sanitize user email

function sanitize_user_email( $email ) {
    return filter_var( $email, FILTER_SANITIZE_EMAIL );
add_filter( 'pre_user_user_email', 'sanitize_user_email' );

This code snippet adds a filter to sanitize the user’s email address before saving it to the database.

Prevent spaces in user_login

function remove_spaces_from_user_login( $username ) {
    return str_replace( ' ', '', $username );
add_filter( 'pre_user_user_login', 'remove_spaces_from_user_login' );

This code snippet removes spaces from the ‘user_login’ field before saving it to the database.

Capitalize first_name

function capitalize_first_name( $first_name ) {
    return ucfirst( strtolower( $first_name ) );
add_filter( 'pre_user_first_name', 'capitalize_first_name' );

This code snippet capitalizes the first letter of the ‘first_name’ field before saving it to the database.

Set default display_name

function set_default_display_name( $display_name, $user_id ) {
    $user = get_userdata( $user_id );
    return $user->first_name . ' ' . $user->last_name;
add_filter( 'pre_user_display_name', 'set_default_display_name', 10, 2 );

This code snippet sets the default ‘display_name’ to the user’s first and last name before saving it to the database.

Validate user_website

function validate_user_website( $website ) {
    return filter_var( $website, FILTER_VALIDATE_URL ) ? $website : '';
add_filter( 'pre_user_user_url', 'validate_user_website' );

This code snippet validates the ‘user_url’ (user website) field before saving it to the database. If the URL is invalid, it saves an empty string instead.