In general, it is difficult to avoid multiple participation. PollUnit can prevent participants from multiple voting with the help of cookie and IP checks. However, a participant from another computer can reopen the poll and vote again.
Nevertheless, there are several ways to protect your online voting from unwanted multiple participations or to reduce them.
Choose your security mechanisms depending on your target group.
Allow multiple participations with one device
If you activate »Allow multiple participations on one device«, a button will be displayed in your PollUnit, through which a new participation under a different name can be started after a participation.
If you choose »Allow only one participation«, a cookie will be set at the participant after casting a vote. This cookie prevents further participation in the user's browser. If the user changes the browsers or deletes their cookies, they can vote again. Cookie protection therefore offers only limited security.
If you activate the IP blocker, the IP address of the participant will be blocked for further participations after a participation. For example, users of companies and universities may use the same IP address. They could then only participate once. Since the IP address can change, this method also offers only limited protection.
If you require an account, only participants who have created a PollUnit account can vote. To create an account, participants need a valid email address which will be verified by us. Only one participation per account or e-mail address is possible.
A very secure method is to only allow users to participate who have received an invitation. For this purpose, PollUnit sends e-mails with a secret code that can only be used once for voting. For this method, participants do not need a PollUnit account. The invitation links can also be sent manually, so you can share them for example via WhatsApp or other messengers.
Invitation and PollUnit account required
Our safest method: it behaves like »Invitation required« with the difference that participants additionally need a PollUnit account. They need to log in or register with PollUnit before voting. The advantage over »Invitation required« is that with an invitation, that does not match the invited email address, you cannot participate. For example, intercepted or stolen invitations cannot be used unless one does also have access to the respective PollUnit account.
The necessary settings can be found in step 4 of your PollUnit Wizard.
You see, it is crucial whether you know your participants or whether they are completely unknown to you. Only if you create a voting with the settings »Invitation required« or »Invitation and PollUnit account required« you can be sure that your invited persons can only vote exactly once.
If you share the participant link to your PollUnit, e.g. on Facebook, and you also allow unknown users who were not invited to vote, we cannot uniquely identify these users. However, we can raise the hurdle to cast a double vote.
If you have further suggestions on how we can secure your vote against multiple participation, feel free to open a feature request in our PollUnit Support Forum.