Document & protect.

In challenging environments, with limited or no internet connectivity or in the face of repression, Tella makes it easier and safer to document human rights violations and collect data.

Get it on Google Play

Tella for iOS is coming soon! Notify me

Why Tella?

If you are an activist, journalist, human rights defender, or anyone who engages in documentation of injustice, you can use Tella to:
Protect yourself from physical and digital repression while collecting and storing sensitive information.

Protect the data you collect from censorship, tampering, interception, and destruction.


Easily  produce high-quality documentation that can be used for research, advocacy, or transitional justice.

Key features

Tella is specifically designed around the needs of those on the frontlines.
Encrypted by default
All of your data is automatically encrypted and inaccessible from the device’s gallery. Unlocking the app by entering the correct security pattern is the only way to decrypt the content.
Customizable forms
Collect the specific data you need with over a dozen different question types (text, multiple choice, geolocation, etc), conditional logic, and data validation.
Direct Upload

If forms aren’t needed, users can instead upload their files directly to the server in just seconds, or set "auto-upload" as soon as they take photos, videos, or record audio. 

Offline mode

If you collect data in remote areas with limited or no internet connection, you can save your data on your device and submit it easily when you reach an internet connection.

Verifiable evidence

When "Verification Mode" is activated, every time you take a photo or a video, or record audio, Tella automatically collects metadata about the file to help others corroborate the evidence.


Tella is currently available in Belarusian, English, French, Portuguese, Russian, and Spanish. And we are always looking to translate Tella into more languages!

Check out Tella’s features in action


Tella is designed for those whose safety is at risk, so it is free to download and use, and it will remain free forever.
Open source
The code for Tella is publicly available so that researchers, security analysts, and developers can freely audit and reuse it.

Tella is a project of Horizontal, a nonprofit organization serving frontline defenders, activists and journalists through digital security support and tool development.

Get it on Google Play