

WhatsApp will display a message within the conversation thread confirming that a message was deleted, but giving away no clues as to what it said. Unfortunately, WhatsApp has no MIB-style neuralyzer: if two blue ticks have appeared to show someone has already read your message, no amount of frantically trying to delete it from the conversation will scrub it from their memory (though it may destroy the evidence). Two blue ticks? Time to leave the country.

If there were two grey ticks then it was delivered, but not read. If there was a single grey tick before you hit ‘Delete for everyone’ then you can rest easy: it hadn’t even been delivered to their phone. The chances are you probably deleted it before they saw it, but the only way to be sure is by using the ticks system that appears at the end of every message, so let’s hope you clocked that before hitting the kill switch. Let’s assume you immediately regretted the sent message, and therefore got to it before they would have done.
