What is metadata?
Metadata is all the information surrounding a message without being part of it: sender, recipient, date, location, frequency. Like an envelope, it stays readable even when the content is encrypted. Cross-referenced, it is enough to reconstruct your relationships and your habits. The topic continues in chapter 4 of my book, Vivre sans Google.
Information verified on July 13, 2026
Look at a postal envelope. The letter is sealed, nobody can read it. Yet the envelope already says a lot: who is writing, to whom, from which city, on what date. Metadata is exactly that: everything surrounding your messages without being their content.
Taken one by one, these traces seem harmless. Cross-referenced, they sketch your entire life. A daily exchange with the same number at 11 pm? A close relationship. Messages to a doctor’s office, then to a lab? Easy to guess the rest. No need to read a single line to know you.
That is where the common belief falls apart. “My messages are encrypted, I’m safe.” Not quite. WhatsApp does encrypt the content of your conversations, but it collects the envelope: your contacts, your schedules, your activity. An app like Signal is designed to keep as little of it as possible. The Signal vs WhatsApp comparison shows the gap in detail.
Where it plays out: chapter 4 of the book helps you move your conversations out of this system, and the Encrypted messaging category compares apps that also protect the envelope.
This topic is chapter 4 of my book
It answers these questions, among others:
- how do you migrate twenty years of email without losing a message or a contact?
- which address can no one ever take away from you, and how do you get it?
- and what do you do with the hundreds of accounts tied to your Gmail?
Forthcoming 22/10/2026 from Éditions Eyrolles
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Tech jargon, translated
Every week in The Spark, I break down one tech story through the privacy lens. And what you can do about it, concretely.
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