[noiz] send: share large files with end-to-end encryption
![[noiz] send: secure file sharing](https://www.noiz.co.za/assets/img/journal/noiz-send-secure-file-sharing.png)
[noiz] send is a free file sharing service run by Noiz at send.noiz.co.za. It encrypts a file in your browser before it is uploaded, so the server stores only data it cannot read, and the link you share expires after a time or a number of downloads that you choose. Files of up to 10 GiB can be sent. It runs Send, the open-source successor to Mozilla's Firefox Send, and needs no account.
Why not just attach it to an email
Email was not designed for large files. Mail servers refuse messages above a size limit, and every copy of an attachment stays in every mailbox it passes through, in sent items, inboxes and backups, for years. A link that expires leaves nothing behind once the file has been collected.
Many file transfer services solve the size problem but hold your file in readable form on their servers. [noiz] send is built so that the service never has the key.
How the encryption works
When you choose a file, your browser encrypts it before anything is uploaded, using 128-bit AES-GCM through the browser's own Web Crypto interface. The browser creates a secret key and adds it to the end of the share link, after a # sign. That part of a web address is not sent to the server when the link is opened, so the server receives the encrypted file but never the key that unlocks it.
The person you send the link to opens it, their browser reads the key from the link, downloads the encrypted file and decrypts it on their own device.
Two consequences follow:
- The link is the key. Anyone who has the full link can download the file until it expires, so send it only to the person who should have it.
- A password adds a second lock. You can set a password on the upload. The server then refuses the download until the password is given. Send the password by a different channel from the link, for example the link by email and the password by Signal.
Limits
| Setting | What you can choose |
|---|---|
| File size | Up to 10 GiB |
| Expiry | 5 minutes, 1 hour, 1 day or 7 days |
| Downloads | 1 to 5, 20, 50 or 100 |
| Several files | Up to 64 files, sent together as one archive |
By default a link allows one download and expires after a day. When either limit is reached, the link stops working.
How to send a file
- Open send.noiz.co.za.
- Drag the file into the window, or select it.
- Choose how long the link lasts and how many downloads it allows.
- Optional: set a password.
- Select Upload and wait for the encryption and upload to finish.
- Copy the link and send it to the recipient.
From Thunderbird
Thunderbird can send large attachments through Send automatically. The free add-on "FileLink provider for Send" encrypts and uploads an attachment to any Send service and puts the link in your message instead of the file. Add it from Thunderbird's add-ons page, set the service address to https://send.noiz.co.za, and choose it as the FileLink service when you attach a large file.
Open source, top to bottom
Send is published under the Mozilla Public License 2.0, and its source code is public, so the encryption described here can be checked by anyone. It is a community fork of Mozilla's Firefox Send, kept alive after Mozilla discontinued the original, and it works with ffsend, a command-line tool for sending files from a terminal or a script.
That openness is why Noiz runs it. A file sharing service asks you to trust it with documents you would not leave lying around, and the strongest reason to trust one is that the design does not require trust: the server cannot read what it stores.
If you have a question about [noiz] send, get in touch.
Sources
Checked 19 October 2026.
- [noiz] send: limits from the instance's own configuration
- Send (timvisee) on GitHub
- Send encryption documentation
- FileLink provider for Send, Thunderbird add-on
Note: while some of this content was produced with the help of AI, the final editing has been done by a real human being.
