# Why we don't store your files — and what we do keep

Source: https://help.strongfolder.com/en/blog/why-we-dont-store-your-files/
Updated: 2026-11-05

> StrongFolder is file sharing without storage: your files go directly from your browser to the recipient's over an encrypted WebRTC connection and are never stored on our servers. We keep only transfer metadata — file and folder names, sizes, number of files — to create the link. If a relay is needed, it forwards and does not store.

"Where do my files go?" is the question I hear most about StrongFolder, and it deserves a
straight answer rather than a slogan. StrongFolder is file sharing without storage: we don't
keep your files, by design. But "we don't store anything" would be untrue, so here is
exactly what we keep, what we never keep, and where our approach has limits.

## What does StrongFolder keep — and what does it never keep?

| | Kept by StrongFolder? |
|---|---|
| File contents | **Never.** Not on upload, not on a relay, not in a backup |
| File and folder names, sizes, number of files | Yes — this is transfer metadata, needed to create the link |
| Your e-mail address | Only if you sign in with Google, to show your list of transfers |
| A copy "just in case" | No such copy exists |

To create the link, the service keeps transfer metadata: file and folder names, sizes and the number of files. When someone opens your link, they see that list — names and sizes —
before they choose where to save. That is why the service needs it.

The contents are a different story. Files are never uploaded to or stored on a StrongFolder server. There is no upload step: the bytes
of your files leave your device only when a recipient connects, and they go to that
recipient.

## How does file sharing without storage work?

Our servers do two small jobs. First, they help the two browsers find each other — this is
called signalling, and it carries connection details and the metadata above, not your files.
Second, they serve the web app itself.

Then the browsers open a WebRTC connection between them. WebRTC encrypts every data channel with DTLS, so the file stream is encrypted in transit on every connection. The file stream
goes over that connection, from your device to the recipient's. If you want the technical
picture, [How WebRTC file transfer works](https://help.strongfolder.com/en/guides/how-webrtc-file-transfer-works/) walks
through it step by step.

## What about the relay?

Sometimes a direct connection is impossible — a strict corporate firewall, some mobile
networks. In those cases the transfer falls back to a StrongFolder TURN relay.

I want to be precise here, because this is where marketing often gets loose. With a relay,
your data does pass through our server. It passes through encrypted, and the relay only
forwards it: it does not write it to disk or keep a copy. So we say "files are never stored
on a server", not "files never touch a server". The second sentence would be false for
relayed transfers, and you deserve the accurate one.

## Why is a stored copy a risk?

Most transfer services work like a locker. You upload the file, they keep it for a set
period — commonly days, sometimes weeks, depending on the service and plan — and anyone with
the link can download it during that time.

Nothing about that is malicious. But every day a copy exists is a day it can be exposed:

- **The link travels.** A link sent to one client gets forwarded to a colleague, pasted into
  a ticket, saved in a chat history. While the copy exists, the link works for whoever has it.
- **Breaches happen to everyone.** A server that holds millions of files is a target. A
  server that holds none is a much less interesting one.
- **You can't verify deletion.** When a service says the file is deleted after seven days,
  you have to trust it — including its backups.
- **Someone else's rules apply.** A stored copy falls under the provider's jurisdiction,
  terms and legal requests, not just yours.

With StrongFolder, the window is the transfer itself. When you click Stop Sharing or close
the tab, there is nothing left on our side to download.

## What are the honest limits of this approach?

Not storing files is a real privacy advantage. It is not magic, and I'd rather you knew the
limits before you rely on it:

- **No password-protected links.** Anyone who has the link can connect while you are
  sharing. Treat the link like a key.
- **The link works only while you share.** The link works while the sender keeps sharing. When the sender clicks Stop Sharing or closes the tab, the files are no longer available. That is a feature for
  privacy and a limitation for convenience.
- **You must stay online.** The sender's browser tab must stay open and online until the recipient finishes downloading — files come from the sender's device, not from a server. If you can't, a cloud link is the better
  tool — [P2P vs cloud file transfer](https://help.strongfolder.com/en/guides/p2p-vs-cloud-file-transfer/) helps you choose.
- **Names are metadata.** We keep file names to build the link. If a name itself is
  sensitive — "Q3-layoffs-final.xlsx" — rename it or put the file in an encrypted archive
  first.
- **Encryption in transit, not with your own keys.** We don't claim end-to-end encryption
  with keys you hold, and we don't claim certifications. For regulated data, check your
  organisation's rules.

## How do I share sensitive files safely with StrongFolder?

A simple routine covers most cases:

1. Send the link only to the people you mean, through a channel you trust.
2. Ask the recipient to confirm when the download has finished.
3. Click **Stop Sharing** straight away.
4. For highly sensitive files, pack them into an encrypted archive (for example 7-Zip with
   AES-256) and give the password by phone or another messenger. This works on top of any
   transfer method.

The full checklist, with email, cloud drives, SFTP and P2P compared, is in our
[secure file sharing guide](https://help.strongfolder.com/en/guides/secure-file-sharing/).

[Send files now](https://strongfolder.com)
## Why did we choose this design?

Partly because I wanted it as a user — I describe that in
[Why I started StrongFolder](https://help.strongfolder.com/en/blog/why-i-started-strongfolder/). Partly because it is simply
cleaner: a service that never holds your files cannot lose them, leak them or keep them
longer than promised. And partly because it keeps things simple for us. We don't run a
warehouse of other people's data, which is one reason StrongFolder is free today, with no
paid plans at the moment.

Everything above is also on our [Security & privacy](https://help.strongfolder.com/en/security/) page, kept up to date. If
anything there is unclear, or you think we should keep even less, write to me at
[info@strongfolder.com](mailto:info@strongfolder.com).

## FAQ

### Does StrongFolder store my files?

No. Files are never uploaded to or stored on a StrongFolder server. To create the link, the service keeps transfer metadata: file and folder names, sizes and the number of files.

### What happens when a relay server is used?

If a direct connection is impossible (strict corporate firewall, some mobile networks), the encrypted stream passes through a StrongFolder relay (TURN) server. The relay forwards the data and does not store it.

### Can I protect a StrongFolder link with a password?

Not at the moment. Anyone with the link can connect while you are sharing. For sensitive files, send an encrypted archive and share its password through another channel.

### How do I make sure nobody else downloads my files later?

Click Stop Sharing or close the tab once the recipient has finished. The link works while the sender keeps sharing. When the sender clicks Stop Sharing or closes the tab, the files are no longer available.