HOIA is the official COVID-19 contact tracing app for Estonia. It is owned by the Estonian Health Board. The app has been created in collaboration between the Estonian Health Board, the Ministry of Social Affairs, the Health and Welfare Information Systems' Centre and a voluntary consortium of Estonian companies.

The application uses Bluetooth and the Google Exposure Notification API to notify you about exposure to people diagnosed with COVID-19. This way the app allows you to take care of yourself and your loved ones while limiting the spread of the disease in Estonia. The app has been developed according to privacy preserving principles and the notifications sent through the app do not disclose the identity of the infected person. Likewise, only you will know if you have been exposed to people diagnosed with COVID-19.

Phones that use the app register the Bluetooth signals from other nearby phones. If the signal is sufficiently close and long enough, an anonymous code referring to a close contact will be stored in the phone. If a person now confirms their infection with the HOIA app, the anonymous codes on their device will be uploaded to a central server where all users can download them. It is not possible to identify a person based on an anonymous code. The user’s phone compares whether the infected person’s anonymous code matches a code previously stored on their phone. If so, the user is considered to be a close contact and they will be notified with instructions. It will not be revealed to the user who the infected person was with whom they were in contact with, or any other information that would allow the indirect identification of the infected person.

The app has been developed in collaboration with the following Estonian companies: ASA Quality Services, Cybernetica, FOB Solutions, Fujitsu Estonia, Guardtime, Heisi IT, Icefire, Iglu, Mobi Lab, Mooncascade, Velvet.

From version Hoia 1.5.2:

An overview of active Covid-19 restrictions added to the app.

Latest: 1.5.2 on April 30, 2022
All versions
Hoia 1.5.2
April 30, 2022


Uploaded:April 30, 2022 at 8:12AM UTC

File size:5.51 MB


Hoia 1.4.9
February 9, 2022


Uploaded:February 9, 2022 at 5:44PM UTC

File size:5.6 MB


Hoia 1.4.7
January 28, 2022


Uploaded:January 28, 2022 at 9:14PM UTC

File size:5.53 MB


Hoia 1.4.6
November 19, 2021


Uploaded:November 19, 2021 at 7:41AM UTC

File size:5.52 MB


Hoia 1.4.5
October 16, 2021


Uploaded:October 16, 2021 at 4:28PM UTC

File size:5.52 MB


Hoia 1.4.1
August 18, 2021


Uploaded:August 18, 2021 at 8:28AM UTC

File size:5.46 MB


Hoia 1.4.0
July 9, 2021


Uploaded:July 9, 2021 at 12:39PM UTC

File size:5.76 MB


Hoia 1.3.8
May 7, 2021


Uploaded:May 7, 2021 at 7:49AM UTC

File size:4.43 MB


Hoia 1.0.9
February 18, 2021


Uploaded:February 18, 2021 at 8:44PM UTC

File size:4.43 MB


Hoia 1.0.8
January 19, 2021


Uploaded:January 19, 2021 at 7:49AM UTC

File size:4.43 MB