When You Need Unique Users but Can’t Force Login

Source: Dev.to

Introduction

I have a course project that requires presenting information and then collecting user data through a survey. A key concern is ensuring that each user submits only one unique response.

Email‑based Authentication

The most straightforward solution is to use an email‑based authentication system (e.g., Google login). While effective, this approach feels like overkill for a simple survey, especially when there is no incentive for participants.

IP‑based Identification

I tried identifying users by their IP addresses. This method quickly showed its limitations:

• IP addresses can change frequently, especially on mobile devices when users travel.
• Even on a home network, I was able to submit multiple votes after some time.
• Refreshing the page did not reset the restriction, indicating a more complex issue.

Cookie‑based Identification

Using cookies to track users also has significant drawbacks:

• Switching devices (e.g., from a mobile phone to a desktop) makes it impossible to prevent multiple responses.
• Some browsers and extensions block cookies by default, reducing reliability.

Conclusion

Reliably identifying unique users without a traditional authentication system (such as Google login) is extremely difficult. Each approach—email authentication, IP tracking, or cookies—has its own advantages and disadvantages, and the best solution depends on the specific requirements and constraints of the project.

Project Link: