What a vCard is, and what your phone does with one

The format behind the "Add to contacts" button. What a .vcf file holds, how iPhone and Android read it, and why a saved copy never updates itself.

A text file from 1995

A vCard is a text file, with the extension .vcf, that describes a person: name, numbers, addresses. The format is thirty years old, and that is exactly its strength. Every phone, every address book, every mail program reads it, with no extra app.

Opened in an editor, a vCard looks like this:

BEGIN:VCARD
VERSION:3.0
N:Dupont;Camille;;;
FN:Camille Dupont
TEL;TYPE=CELL:+41 21 000 00 00
EMAIL:camille@example.ch
END:VCARD

Each line is a field. Nothing is hidden.

What a vCard can hold

A lot more than most people put in it: first and last name separately (so sorting works), company and job title, several phone numbers with their type, several e-mail addresses, a postal address, a website, social profiles (LinkedIn, Instagram), a photo, and a free note.

The field that makes the difference in an address book is the web address: it is the only one that stays true when everything else changes, provided it leads to a page you keep up to date.

What your phone does when it receives one

On iPhone, opening a .vcf file shows a pre-filled "New contact" card with a button to save it. On Android, the Contacts app offers the same. The file can arrive by e-mail, AirDrop, message, or from a link on a page: the "Add to contacts" button on a Vizy card is nothing more than a link to a vCard generated at that moment.

Once saved, the contact belongs to the phone. It syncs with iCloud or Google like any contact typed in by hand.

The photo, and why it is often missing

A vCard can carry the photo in two ways: as a link to an image online, or embedded directly in the file. Many services choose the link, because it is lighter. Address books, though, often ignore that link, and the contact stays faceless.

To make sure the photo arrives, it has to be embedded, as JPEG or PNG (the more modern WebP is not understood by contacts apps). That is what Vizy does: a small image, a few dozen kilobytes, slipped into the file.

What a vCard does not do: update itself

This is the limit worth knowing. A vCard is a copy. The day you change your number, the contacts already saved on other people's phones do not move. No file format can do otherwise.

The remedy fits in one line: put in the file the address of a page that does update. The contact then keeps two things, a copy of the moment, and the way to the living version. That is the reason for a digital business card alongside the vCard, rather than instead of it.

Making one

Without installing anything: on iPhone, open your own card in Contacts and choose "Share Contact"; on Android, "Export" in the contact's menu. You get a .vcf to send.

With a page: the vCard is produced on request, from what the page shows, so it is always current. On Vizy it is the button at the foot of every card, and the file carries the photo.