On its website https://www.whatsapp.com/faq/en/general/20951546 page website de manera oficial sovelluksen FAQ:sta updated FAQ section FAQ section preguntas frecuentes blue tick indicates conferma di lettura https://www.whatsapp.com/faq/en/general/20951546 Whatsapp more details on single check mark via WhatsApp website blue check marks faq-pagina page auf seiner Seite mit updated FAQ On its website updated FAQ Kaynak WhatsApp FAQ preguntas más frecuentes updated FAQ infamous blue double check updated FAQ Deep Sheth conferma di lettura the answer turn blue FAQ updated FAQ What are those check marks next to my messages? double blue tick feature