Read receipt

A read receipt is a tiny state machine parked in the corner of a message. The states are the same everywhere because the network makes them so: the message left this device, the message arrived on that device, the recipient’s app reported it on screen. Three facts, each one weaker than it looks, and the marker’s job is to report which of them has happened without pretending to more.

The drawing is where the agreement ends. One tick then two ticks, ticks that change colour, a filled circle then a hollow one, the recipient’s avatar sliding along under the thread, the word “Seen” with a timestamp: every one of these is somebody’s convention and none of them is a standard. There is no specification, no platform guidance, and no shared meaning for the second tick’s colour, which is why the phrase “blue ticks” identifies exactly one product and means nothing on any other. The term travels perfectly. The glyph does not travel at all, so a marker needs a text alternative and a legend somewhere, and a screenshot of one product’s ticks teaches nothing about another’s.

Products also disagree about what “read” means, and the disagreement is not a detail. In some it means the conversation was on screen, whether or not anyone was looking. In others it means the message scrolled into view. In some it fires when a notification is expanded on a lock screen. Group chats fragment the question further, since a message can be read by four people out of nine, and the marker has to choose between the earliest reader, the last one, and a count. This is why the same marker means “she is ignoring me” to one person and nothing at all to another, and why so many products make the whole feature switchable, often symmetrically: turn yours off and you stop seeing everyone else’s.

The design consequence is to keep the marker’s claim as narrow as its evidence. Prefer the weakest true word over the strongest available one, put delivery and reading in different states rather than collapsing them, treat the timestamp as part of the claim, and never place the marker where it reads as being about the whole conversation instead of one message. A status that overstates itself does not just misinform, it changes how the reader feels about a silence, which is a large thing to do with fourteen pixels.