Advanced online election counting

Count instant runoff and single transferable vote elections for free, no downloads or sign-up required

Screenshot of OpenTally

Key features

Runs in your browser

No downloads or sign-ups are required. OpenTally counts are computed entirely inside your browser, and no data ever leaves your computer.

Wide range of STV systems

OpenTally supports Gregory (inclusive and exclusive, weighted and unweighted), Meek and Wright variants of the single transferable vote.

Support for arbitrary constraints

OpenTally is the only publicly available election counting software to support arbitrary combinations of constraints, such as gender quotas and other affirmative action requirements.

Free and open source

Source code for OpenTally is publicly available under the GNU AGPLv3.

From our blog

Latest news and posts from the OpenTally blog

Blog
The failure of unweighted inclusive Gregory STV

The single transferable vote (STV) is a family of voting systems designed to achieve proportional representation. It is widely used in Australia in multi-winner elections, in both governments and private contexts.

Most STV systems in use in Australia fall into one of two categories: exclusive…

Blog
A conceptual primer on the single transferable vote

The single transferable vote (STV) is a family of multiple-winner voting systems which provide proportional representation by allowing voters to rank candidates in order of preference.

This series provides a primer on the principles of STV, from its conceptual foundations through to contemporary developments in…

Dev Log
Parcels? Subparcels? Not just for STV hand counts!

Single transferable vote rules designed for hand-counting often contain references to ‘parcels’ (or ‘bundles’ or ‘batches’), ‘further parcels’ and sometimes even ‘subparcels’.

For example, consider the 4th stage of the ERS97 model election. 107 of Glazier's and Wright's ballot papers are aggregated according to…