Start with the question, not the file
Shared moments asks a narrow question: could two people have a place and time in common? A full photo contains far more than that question requires. It can show faces, a home, a document or details the person never meant to share.
With one permission, the app reads the capture time and location of photos from the last two years, right on the phone. Each location becomes an area of about 150 m and each time a one-hour slot. Only that area and hour are sent to Blink’s servers to compare. The images, their file addresses, exact coordinates and complete metadata never leave the phone.
A photo without a place adds nothing
Screenshots, images saved from messages and photos taken with location switched off carry no place. They are skipped. Nothing is guessed, so a photo without a place simply adds nothing.
Capture times come from the photo library itself. Browsers cannot read a library this way, so in Blink on the web you choose the photos and only their place and time are read, inside the browser.
A tolerance is not proof
Two footprints are the same moment when they share an area within two hours, the same day when they share an area on the same day, and the same place otherwise. These are tolerances for a possible shared moment, not proof that people met or stayed somewhere.
Photo places are limited to 4,000 area-and-hour records from the last two years. Location uploads are limited too. Deleting your photo places also deletes the copy on Blink’s servers.
What the server sees
To find crossings with other members, footprints are stored on Blink’s servers: an area and an hour, nothing more. Uploads are limited to prevent misuse. For a same-place crossing, Blink shows neither where nor when, so a match never reveals someone’s routine or precise trail.
This website does not run that comparison or request a photo or location permission. The design principle is straightforward: answer the smallest useful question with the least necessary information.
Maybe you’ve already crossed paths.