How to Add a Custom Favicon to Your WordPress Site Easily

Code

// Function to add a custom favicon to a WordPress site
function wp_dudecom_add_custom_favicon() {
    // Ensure the favicon URL is valid and secure
    $favicon_url = esc_url( get_stylesheet_directory_uri() . '/images/favicon.ico' );

    // Output the favicon link in the head section
    echo '<link rel="icon" href="' . $favicon_url . '" type="image/x-icon" />';
}
add_action( 'wp_head', 'wp_dudecom_add_custom_favicon' );

// Function to add favicon support in the WordPress Customizer
function wp_dudecom_customize_register( $wp_customize ) {
    // Add a section for the favicon
    $wp_customize->add_section( 'wp_dudecom_favicon_section', array(
        'title'    => __( 'Favicon', 'textdomain' ),
        'priority' => 30,
    ));

    // Add a setting for the favicon
    $wp_customize->add_setting( 'wp_dudecom_favicon', array(
        'default'           => '',
        'sanitize_callback' => 'esc_url_raw',
    ));

    // Add a control to upload the favicon
    $wp_customize->add_control( new WP_Customize_Image_Control( $wp_customize, 'wp_dudecom_favicon', array(
        'label'    => __( 'Upload Favicon', 'textdomain' ),
        'section'  => 'wp_dudecom_favicon_section',
        'settings' => 'wp_dudecom_favicon',
    )));
}
add_action( 'customize_register', 'wp_dudecom_customize_register' );

// Function to output the customizer favicon in the head section
function wp_dudecom_customizer_favicon() {
    // Get the favicon URL from the customizer setting
    $favicon_url = get_theme_mod( 'wp_dudecom_favicon' );

    // If a favicon URL is set, output the link
    if ( ! empty( $favicon_url ) ) {
        echo '<link rel="icon" href="' . esc_url( $favicon_url ) . '" type="image/x-icon" />';
    }
}
add_action( 'wp_head', 'wp_dudecom_customizer_favicon' );