RCTab, formerly the RCV Universal Tabulator (RCVUT), is a federally tested open-source software that can tally ranked choice voting (RCV) election results using cast vote records (CVRs) from most voting system vendors. In addition, RCTab can be used to verify RCV results generated by other voting systems. RCTab is the most comprehensive RCV tabulation module to be tested under the Voluntary Voting System Guidelines (VVSG) and the first open-source software to meet VVSG standards. Download the software along with instructions on how to install and use the tabulator by clicking the button at the bottom of this page. An 8 minute video is also available at the bottom of this page that further explains the reason for the existence of RCTab.

RCTab is available under the Mozilla Public License Version 2.0.

A visualizer, RCVis, which uses JSON files produced by RCTab, is also available.

If you are interested in using the tabulator for an RCV election, email us at info@rcvresources.org, and we can provide the support you need to use it in your jurisdiction.

Where is RCTab Used? 

RCTab is currently used to produce official RCV results, as a testing tool, or as an auditing tool. The State of New York certified RCTab for use in single-winner RCV elections in the State, the State of Utah certified RCTab for use in local RCV elections, and the State of Michigan certified RCTab for use in Eastpointe, Michigan’s RCV elections. The Democratic Parties of Alaska, Kansas, and Wyoming used RCTab to produce district- and county-level results in their 2020 Presidential Preference Primaries using RCV. RCTab has been accepted by a federal voting system standards working group as a well-documented, precise implementation of the RCV rules used in U.S. RCV elections. Benton County, Oregon, also used RCTab as a verification tool in the testing and certification process for the RCV tabulation software provided by its voting system vendor, ES&S. Successful replications of past RCV election results have been run on results in San Francisco, California, Minneapolis, Minnesota, the State of Maine, and several other RCV jurisdictions. RCTab successfully tallied RCV elections for the Student Government Association at the University of Houston in January 2019.