About Signalboost

Signalboost was born out of a need we saw in the movement space: to empower people to quickly amplify their message to thousands of people and directly engage those who want to get involved, in a secure and private way.

In an industry that prioritizes aggressive growth and monetization, we want to build something small, well-considered, and impactful for our community.

As of November 2020, Signalboost is a fiscally sponsored project of the nonprofit Aspiration Tech. We cover our operating costs via grants and donations from our community.

The technology

Signalboost is a message forwarding service that uses (but is not affiliated with!) Signal Messenger to deliver messages. Our software enables Signalboost to programmatically purchase a number and from then on out, admins can broadcast messages to subscribers from that number or use it as a hotline.

Your privacy and safety

No app is perfect when it comes to your digital privacy, and we don't purport to be.

We're a big fan of Signal's built-in security features such as world-class encryption and disappearing messages (which we enable by default).

One of the best reasons to use Signalboost is that admins and subscribers don't have to reveal their phone numbers, and thus their identities.

However, in order to make that possible we store the lists of the admins and subscribers. We have deeply considered what it means to be good stewards of this data, and highly encourage you to understand these tradeoffs by reading our Privacy Policy.


Signalboost is a beta technology! We try our best to monitor uptime and make message delivery go fast, but sometimes our infrastructure comes under heavy load.

Subscriber limits

After your channel hits 500 subscribers, new users will be prevented from subscribing until existing subscribers leave.

If you are in an urgent situation and would like to request a larger channel you can do so by sending us a special request via Signal message via our helpline +1-947-800-5717. We are working hard to support channels over 500 subscribers, but that work requires time and resources. You can help us get there by donating!

Message delivery delays

Your channel will also take longer to send broadcasts the bigger it grows: ~1-2 minutes on a channel with 250 subscribers vs. ~5-10 minutes on a channel with 500 subscribers.


To learn about how to request a channel and use it, check out our How-To Guide.

If you want to reach us, you can send us an email at signalboost@protonmail.com (or, if you prefer old-school: signalboost@riseup.net + PGP).

Read our code of conduct here.

Read our source code here.