How Senderly moves your files safely

The flow

Every transfer follows the same four steps, whether you send to a stranger or between your own devices.

1. 1

   Pick your files or a folder

   Choose the files or an entire folder right in your browser. Nothing uploads yet — Senderly first reads them locally to prepare the transfer. Folder structure is kept intact for the recipient.

2. 2

   Encryption happens on your device

   Before a single byte leaves, your browser encrypts the contents end-to-end. Even the file names are encrypted. The key stays with you and the recipient, never with our servers.

3. 3

   Choose how it travels

   Share a link, use a Nearby code with someone next to you, pick one of My Devices you already trust, or send over your local network. You choose the path that fits the moment.

4. 4

   The recipient downloads and decrypts

   On the other end, the encrypted stream is pulled and decrypted directly in the recipient's browser. Only then does the real content exist in readable form — on their device, not on ours.

The security model

A few design choices work together to keep transfers private and hard to tamper with.

• End-to-end encryption

  Content and file names are encrypted before upload. The server is blind — it relays ciphertext it cannot read and cannot help anyone else read.

• Anti-MITM verification (SAS)

  For direct transfers, both sides see a short phrase or code. If the two screens match, no attacker sits in the middle. A mismatch means stop.

• No account for the basics

  Sending and receiving a transfer needs no sign-up. Accounts unlock extras like saved devices and your vault, not the core privacy.

• Local network or relay

  When both devices are on the same network, data can travel directly over the LAN. Otherwise Senderly relays the encrypted stream — still without reading it.

• Automatic resume

  If a connection drops mid-transfer, Senderly can pick up where it left off instead of starting over, so large transfers survive flaky networks.

What we can and can't see

We believe in being honest about metadata. Here is exactly what our servers can observe about a transfer — and what they never can.

In short: the server can see enough to move bytes and enforce limits, but never enough to know what you sent.

Try it yourself