Belenios

Free plan Self-hostedWeb

What Belenios is

Belenios is an online voting system for elections and referendums, including elections for scientific councils and sports associations. Its hosted platform supports standard candidate selection and preferential ballots using Condorcet, Single Transferable Vote, and Majority Judgment. Votes are encrypted so individual choices cannot be learned, subject to how the election's decryption keys are set up. Voters can check that their ballots appear in a public ballot box, and anyone can verify that the result matches those ballots. The hosted service allows up to 2500 voters per election; the site suggests institutional hosting for larger elections. Belenios is also free software under the GNU Affero General Public License version 3, with source code available to run a voting server. Election setup has important constraints: voter lists and email addresses cannot be changed after voting starts. The setup guide recommends shared keys managed by trustees; a lost trustee key means the election cannot be tallied and is canceled. The service is provided as is, with no hotline, and directs questions to its FAQ and discussion mailing list.

Who it suits

Belenios may suit organizations running elections or referendums that need verifiable ballots and candidate or preferential voting. Larger elections can consider its self-hosted option, while hosted elections are limited to 2500 voters.

What it does well

Free hosted platform for up to 2500 voters
Supports Condorcet, STV, and Majority Judgment
Voters can check ballots in the public ballot box
Source code is available for self-hosting

What to know first

Voter lists cannot be changed after an election starts
Lost trustee key prevents tallying and cancels the election
Does not protect against stronger voter coercion
No hotline; support is through FAQ and mailing list

Limits

The hosted platform allows up to 2500 voters per election. After an election starts, voters cannot be added and their email addresses cannot be changed; a new election must be started to remedy this. If a trustee loses a decryption key, the election cannot be tallied and is canceled.

Plans

Plan	Billed and limits	Price
Belenios hosted platform	up to 2500 voters per election · service provided as is, with no guarantee	Free

As belenios.org lists them, read 8 Oct 2026. The maker's own page has the final word.

Getting started

Visit the Belenios website
Use the hosted web platform or download the source code to run a voting server
For the hosted platform, select a supported authentication method: public accounts, Google login, or CAS
Set up the election and voter list before starting it
Follow the setup guide's recommendation for trustee-managed shared decryption keys

Verdict

Belenios offers ballot privacy and public verification, with several preferential voting methods on its hosted platform. Election setup, key management, and the hosted voter limit need careful consideration, especially for high-stakes use.

Questions

Does Belenios cost anything?

The hosted platform is free, with a listed price of $0. It is provided as is, with no guarantee.

Can I run Belenios on my own server?

Yes. Belenios is free software under the GNU Affero General Public License version 3, and its source code can be downloaded to run a voting server.

Which voting methods does the hosted platform support?

It supports standard candidate selection and preferential elections using Condorcet, Single Transferable Vote, and Majority Judgment. Weighted votes are supported for standard elections only.

How can voters authenticate?

The hosted platform supports public accounts, Google login, and CAS authentication.

What happens if a trustee loses a decryption key?

The election cannot be tallied and is canceled.

Does Belenios prevent voter coercion?

Its FAQ says it does not protect against stronger coercion in which voters may be forced to disclose credentials or passwords. It describes security for high-stakes online voting as an unresolved challenge.

Facts from Belenios's own pages

Authentication: The hosted platform supports public accounts, Google login, and CAS authentication. · vote.belenios.org, 8 Oct 2026
Election setup limit: Voters cannot be added and their email addresses cannot be changed after an election starts; the stated remedy is to start the election again. · belenios.org, 8 Oct 2026
High-stakes suitability: The FAQ says Belenios does not protect against stronger coercion where voters may be forced to disclose credentials or passwords, and describes high-stakes online voting security as an unresolved challenge. · belenios.org, 8 Oct 2026
Hosted service limit: The hosted platform allows up to 2500 voters per election; the site suggests institutional hosting for elections above that limit. · vote.belenios.org, 8 Oct 2026
Maintainers: The free online platform is maintained by Véronique Cortier and Pierrick Gaudry, and the about page says software development moved to a startup independent of the research teams starting in 2025. · belenios.org, 8 Oct 2026
Privacy data: The GDPR page says Belenios processes language and session cookies, email addresses used for voting material and confirmation, encrypted ballots, and connection information and vote dates. · belenios.org, 8 Oct 2026
Purpose: Belenios is a verifiable online voting system for elections and referendums, including elections for scientific councils and sports associations. · belenios.org, 8 Oct 2026
Self-hosting: Belenios is free software licensed under the GNU Affero General Public License version 3, and its source code can be downloaded to run a voting server. · belenios.org, 8 Oct 2026
Support: The platform is provided as is, has no hotline, and directs users to its FAQ and discussion mailing list for questions. · vote.belenios.org, 8 Oct 2026
Trustee security: The setup guide recommends trustee-managed shared decryption keys; if a trustee key is lost, the election cannot be tallied and is canceled. · belenios.org, 8 Oct 2026
Verifiability: Voters can check that their ballots appear in the public ballot box, and anyone can verify that the result corresponds to the ballots. · belenios.org, 8 Oct 2026
Voting methods: The hosted platform supports standard candidate selection and preferential elections using Condorcet, Single Transferable Vote, and Majority Judgment. · vote.belenios.org, 8 Oct 2026
Voting privacy: The system encrypts votes so that no one can learn an individual voter's vote, subject to the election's decryption-key setup. · belenios.org, 8 Oct 2026
Weighted votes: Weighted votes are supported for standard elections only. · vote.belenios.org, 8 Oct 2026

Where Belenios stands on Freedom251

Online Voting Software#4 of 31