AlterSend

What is AlterSend?

AlterSend is an open-source app that sends files end-to-end encrypted, to any device or to anyone with a link. There is no cloud storage, no accounts, and no size limit on a direct transfer. Pairing uses a QR code or a short code.

What AlterSend does

A transfer can be a text note, a single file, or a whole folder. The page says a 1 KB snippet and a 200 GB project move the same way. Files only exist on the two devices involved, and nothing is written in between. Keys for every session are held only by the devices, and the secret never leaves the OS keychain. When devices can't connect directly, an encrypted relay forwards the data, and the relay can't read the files. Relay-routed transfers are capped at 20 GB between apps and 10 GB for browser links. Direct transfers stay unlimited. Run your own relay to remove the cap. Pro lifts it. A link downloads in the browser with no install and no account, and browser links cap at 10 GB because they go through the relay. An interrupted transfer resumes instead of starting over. Same room or different continents, the connection is direct either way.

Who AlterSend is for

The page is for editors, photographers, and private teams. Workflows on the page include video editors, photographers, developers, confidential and regulated work, music producers, and architects.

How AlterSend works

Pair once with a QR code or a short code. After that the devices recognize each other, and files move straight between them. Share a link and the download happens in the browser, with nothing to install and nothing to sign up for. The pages list Web, Mac, Windows, Linux, iOS, iPhone, and Android. The client is Apache-2.0.

Key features

• End-to-end encrypted transfers, with keys for every session held in the OS keychain.
• No cloud storage, no accounts, and no size limit on a direct transfer.
• Browser links need no install and cap at 10 GB, because they go through the relay.
• Relay cap is 20 GB between apps. Direct transfers stay unlimited. Pro lifts the relay cap.
• An interrupted transfer resumes instead of starting over.
• Text note, single file, or whole folder, including a 1 KB snippet or a 200 GB project.
• Remove a device from the paired list after you replace it. Only a public key was stored for it.
• Platforms listed: Web, Mac, Windows, Linux, iOS, Android, and iPhone.

Facts from altersend.com, checked 14 October 2026

• Works in the same room or on different continents.
• Even a relay transfer stays end-to-end encrypted.
• AlterVault is a second app for photos, videos, and documents behind a PIN, encrypted on the phone, with nothing uploaded.
• Use cases on the page include a 300 GB project, RAWs, music stems, and Revit, CAD, and point clouds.

Written from AlterSend's own website (Homepage, Features). The maker can claim this listing to edit it.