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COVID Symptom Survey

Since April 2020, Delphi has conducted a voluntary COVID-19 symptom survey, distributed daily to users in the United States via a partnership with Facebook. This survey asks respondents about COVID-like symptoms, their behavior (such as social distancing), mental health, and economic and health impacts they have experienced as a result of the pandemic. A high-level overview of the survey is posted on the COVIDcast website.

Geographically aggregated data from this survey is publicly available through the COVIDcast API as the fb-survey data source. Demographic breakdowns of survey data are publicly available as downloadable contingency tables.

This documentation describes the survey items, data coding, data distribution, and the survey weights computed by Facebook. It also documents the individual response data, which is available to researchers with a signed Data Use Agreement. If you are a researcher and would like to get access to the data, see our page on getting data access.

If you have questions about the survey or getting access to data, contact us at


The COVID Symptom Survey is a project of the Delphi Group at Carnegie Mellon University. The Principal Investigator is Alex Reinhart; Wichada La Motte-Kerr is Survey Coordinator. The survey protocol is reviewed by the Carnegie Mellon University Institutional Review Board.

The support of several institutions makes the survey possible. Facebook supports the survey through recruitment (participants are invited via their News Feed), survey sampling and weighting procedures, technical assistance in survey design and implementation, and coordination with researchers and public health officials. The University of Maryland’s Joint Program in Survey Methodology conducts an international version of the survey, and we coordinate closely on survey design and implementation. Delphi collects, aggregates, and distributes the US survey data, and retains ultimate responsibility for the US survey instrument and data.

We develop the survey collaboratively with data users, public health officials, and others. If you are interested in getting involved, see our collaboration and survey revision information.

Citing the Survey

Researchers who use the survey data for research are asked to credit and cite the survey in publications based on the data. Specifically, we ask that you:

  1. Include the acknowledgment “This research is based on survey results from Carnegie Mellon University’s Delphi Group.”
  2. Cite this web page for details about the survey. For example, you may cite it as

    Delphi Group (2021). COVID Symptom Survey.

    A journal article describing the survey and its methods is currently in preparation, and we will update this page when it is available so that you can cite it instead.

  3. Send a copy of your publication, once it appears publicly as a preprint or journal article, to

Additionally, please note that the data use agreement requires that if you disclose survey microdata, Delphi must agree on the aggregation method that you will use to ensure reported estimates do not disclose any individual identifiable information, including individual survey results. If you are unsure whether a particular aggregation will prevent disclosure of individual survey results, please email us at

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