The Österreich forscht platform (www.citizen-science.at) was founded in 2014 with the aim of (1) networking citizen science stakeholders in Austria, (2) providing as comprehensive an overview as possible of citizen science projects in Austria, and (3) generally developing the citizen science methodology. In 2017, on the initiative of the Österreich forscht platform, many institutions active in citizen science joined forces in the Citizen Science Network Austria and committed themselves to promoting the quality of citizen science in Austria (https://www.citizen-science.at/netzwerk). An important step in promoting quality was the establishment of transparent criteria that projects wishing to be listed on the Österreich forscht platform must fulfil. The aim of these criteria is to guarantee and further improve the quality of the projects presented on the platform. This catalogue is the third version (1.2) of the criteria; the previous versions are linked at the end of the preamble. From March 2017 to February 2018, a working group of the Österreich forscht platform, consisting of representatives from 17 institutions, developed version 1.0 of the criteria, which enable a transparent evaluation of projects that want to be listed on Österreich forscht. In addition, the criteria should enable citizen scientists to make an informed decision about whether they want to participate in the project. Version 1.0 of the Quality Criteria was presented to the public at the 4th Austrian Citizen Science Conference (ÖCSK) from 1-3 February 2018. The Quality Criteria became valid on this date. Suggestions for changes to the criteria were already made by participants at the 2018 ÖCSK, and were incorporated into version 1.1 by the working group immediately afterwards. Therefore, as of 13 October 2023, all projects on Österreich forscht comply with the quality criteria of version 1.1. During the development of the quality criteria, it was decided that they would continue to be adapted as necessary to meet new challenges and developments. The version number of the criteria to which a project conforms can be found on the project page. In version 1.2, in particular, the criteria for ethical aspects in citizen science projects have been adapted to current developments in 2024.