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

Dev Log
Battery of optimisations leads to 108% performance improvement

Using rational arithmetic, OpenTally e825ca1 processes the 3,821,539-vote 2022 Australian Senate election for Victoria in a mean 11.34 (95% CI ± 0.03) seconds on my Intel i5-7500. This week I put some time into cutting this figure down.

Using perf and Hotspot, we obtain…

Later-no-harm and the ‘Wright’ method of single transferable vote

Later-no-harm is a criterion for preferential voting methods which provides that ‘Adding a later preference to a ballot should not harm any candidate already listed’ [1]. The most well-known voting systems which comply with later-no-harm are the single transferable vote (STV), and its single-winner…

Curiosities in drafting for the weighted inclusive Gregory method of STV

In Australia, 2 jurisdictions make use of the weighted inclusive Gregory method of the single transferable vote (STV). The weighted inclusive Gregory method of STV is one of 2 systems recommended by the Proportional Representation Society of Australia as part of a gold standard electoral…