How metadata works
Almost everything digital carries a second layer of information describing it.1 Some of it is needed for the thing to work: a mail server has to know the recipient’s address to deliver a message, and a phone network has to know which number you dialed. Some of it is added quietly by the device or app that made the file. Either way, it is created automatically and you rarely see it.
| Where | The metadata | What it can show |
|---|---|---|
| Sender, recipients, date, servers on the route, sometimes the sender’s IP address | Who you deal with, how often, and at what hours | |
| Phone calls | Numbers, time and length of each call | Your relationships and routines |
| Photos | Date, camera model, often GPS coordinates | Where you were, and when |
| Web browsing | Your IP address, the sites you look up, the time of each visit | Your interests, your location and your daily pattern |
Why metadata matters
It is tempting to think only content is private. But a call to a clinic, a message to a lawyer at midnight or a daily email to the same address tells a story without a single word of content. Metadata is also structured, so it is far easier to collect, store and search in bulk than conversations are.
Researchers at Stanford tested this with the phone records of more than 800 volunteers. They concluded that telephone metadata can be used to re-identify people and to draw sensitive inferences about them, including about their health.2
Metadata and encryption
Encryption protects what a message says. The information needed to deliver it has to stay readable to the systems doing the delivering. An email’s header lists the sender, the recipient and the route, and those fields are how mail servers know where to send it.3 So privacy has two parts: protecting content with encryption, and giving away less metadata to begin with.
How to give away less metadata
- Use email aliases, so companies can’t connect your accounts through one address.
- Block tracking pixels, which add when and where you opened a message to what the sender knows.
- Use a VPN, so the websites you visit see the VPN’s IP address instead of yours.
- Remove location from photos before sharing them. Phones let you turn location off when you share a picture.
Where you’ll see the word
You’ll see “metadata” in privacy policies, in news about surveillance and data requests, and in the details panel of any photo or document on your device.
Metadata in Secria
Secria is built to give away less. In Secria Mail, tracking pixels are removed automatically and senders never see your IP address, and aliases keep your main address out of other companies’ databases. Secria VPN keeps no activity logs: we do not record browsing, DNS queries or traffic contents.
Related terms
Sources
- NIST Computer Security Resource Center, Glossary: metadata.
- Jonathan Mayer, Patrick Mutchler and John C. Mitchell, Evaluating the privacy properties of telephone metadata, Proceedings of the National Academy of Sciences (2016).
- IETF, RFC 5322: Internet Message Format (October 2008).
Checked October 2026. Secria facts are from our Mail and VPN pages and the whitepaper.
Questions about metadata
What is an example of metadata?
The date and location stored inside a photo, the sender, recipient and time of an email, and the number and length of a phone call are all metadata. None of them is the content itself, but each describes it.
Is metadata encrypted?
Often not. Encryption usually covers the content of a message or file. The information needed to deliver it, such as addresses and timestamps, generally has to stay readable to the services that carry it.
Can metadata identify me?
Yes. Patterns of who you contact, when and from where are often unique to one person. Research on phone records has shown that metadata alone can be used to re-identify people and infer sensitive details.
How do I remove metadata from a photo?
Turn off location when you share the photo, which phones offer in the share menu, or export a copy without location data. Many messaging apps and social networks also strip photo metadata when you upload.