/**
 * Get favicon for a URL or domain as base64 string using Google's favicon API
 */
export declare function getFaviconForDomain(urlOrDomain: string, formatBase64?: boolean): Promise<string>;
/**
 * Extract TLD and hostname from domain in Regex. There's two or more part
 * TLDs (https://en.wikipedia.org/wiki/List_of_Internet_top-level_domains)
 * so it is hard to tell if host.secondTLD.tld or host.tld is correct way
 * to get root domain (e.g. abc.go.jp, abc.co.uk)
 */
export declare function convertURLToDomain(domain: string): string;
/**
 * Checks if a string is a valid URL.
 */
export declare function isURLValid(url: string): boolean;