The Swiss Election Study (Selects) 2019 consists of four complementary components: The Post-Election Survey (PES), the Panel Survey, the Candidate Survey, and the (Social) Media Analysis. The main difference compared to previous studies relates to the mode of data collection; the main emphasis was moved towards web questionnaires. The mode for the Post-Election Survey 2019 was web/paper whereas in 2015, it was web/telephone. As in previous election studies, novel thematic modules of particular salience to researchers were included in the different surveys, while keeping the necessary continuity in the core questionnaire of the Post-Election Survey for comparison with previous waves. Post-Election Survey (PES): The Post-Election Survey consists of 6664 respondents. The survey was conducted in a sequential mixed mode with web offered as the first option: 82% responded in this way, while 18% responded by returning the paper questionnaire that was sent out later to those not having completed the web questionnaire. The sampling was based on a representative sample of around 2’600 Swiss citizens, with an oversampling of small cantons to have at least 50 respondents in every canton. An additional oversampling was done in the cantons of Zurich, Geneva, and Ticino thanks to additional funding from these cantons. Panel Survey: The Panel Survey studies the evolution of opinion and vote intention/choice during the different phases of the election cycle. In 2019, three waves were conducted: the first before the main campaign period (Mai/June), the second during the election campaign (September/October), and the third after the elections (October-December). 7939 individuals responded to the first wave, 5577 to the second wave, and 5125 to the third wave. 4654 individuals responded to all three waves. This three-wave panel will be continued with annual follow-up waves until the 2023 elections. At the end of wave 3, 3'030 respondents gave consent to be contacted for the yearly waves. Wave 4 took place between September 28 and November 2nd, 2020 with 2'499 respondents. Wave 5 took place between September 27 and November 1st, 2021 with 2’323 respondents. Wave 6 took place between September 26 and November 6, 2022 with 2’178 respondents. The final wave 7 took place between October 23 and December 11, 2023 with 2'470 respondents. Candidate Survey: The Candidate Survey was carried out among all candidates for the National Council and the Council of States in the framework of the international Comparative Candidate Survey (CCS) project, based on the Round III questionnaire. The survey collects data on the biography, campaign activities, and policy position of the candidates. Among others, the information gathered makes possible the study of underlying factors of candidates’ electoral success, as well as of issues of representation and linkage between voters and elites. In 2019, 2158 out of 4736 candidates participated in the Candidate Survey. This survey was conducted by Politools.net on behalf of Selects. (Social) Media Analysis: On behalf of Selects, the Digital Democracy Lab of the University of Zurich conducted a Media Analysis. The Media Analysis is a supplement to the Panel Survey and makes it possible to analyse the election campaign in the media and its influence on the formation of voters' opinions. In addition to the content analysis of the coverage of traditional media (print and online), which has been carried out in the context of Selects since 2003, the Media Analysis 2019 also includes, for the first time, the election campaign communication of parties and candidates on social media. For this Social Media Analysis, the Twitter accounts of 1284 candidates, parties, and organizations were taken into account, as well as the Facebook pages of 261 candidates.