esc_url()

esc_url() — Checks and cleans a URL. A number of characters are removed from the URL. If the URL is for displaying (the default behavior) ampersands are also replaced. The {

Inputs: $url (string): The URL to be cleaned. $protocols (string[]): Optional. An array of acceptable protocols. Defaults to return value of wp_allowed_protocols(). $_context (string): Private. Use sanitize_url() for database usage.

Returns string: The cleaned URL after the ‘clean_url’ filter is applied. An empty string is returned if $url specifies a protocol other than those in $protocols, or if $url contains an empty string.