With the emergence of the concept of crowdfunding, a new alternative has arisen for non-profit organizations to procure funding for their cause. But several of the issues plaguing non-profits still remain. Attracting people to give in the first place is one major challenge, but retaining the relationship and keeping the donors giving is an even bigger one. This thesis delves into the issue of getting donors to sustain their giving, more commonly known as donor retention. More specifically, this thesis aims to identify what factors are important when aiming to improve donor retention in both charity and crowdfunding contexts. Additionally, the thesis explores what is important in the general structure and content of a non-profit crowdfunding platform, and what possible measures can be taken in order to improve donor retention through the platform. This was achieved by conducting a literature study in the field of donor retention in both a charity as well as crowdfunding context to find important factors as well as measures to be considered. In parallel, 15 interviews were conducted to gather insights on the attitudes, donation habits and motivations of people who had previous experience of giving to charity. In sequence with the interviews, 15 user tests on the crowdfunding platform of the non-profit organization Help to Help were performed. The user tests aimed to evaluate and collect donors' opinions and conceptions of the contents and layout of an existing non-profit crowdfunding platform. From the literature study several factors found to improve donor retention were identified. These were: satisfaction, trust, commitment and involvement. The literature study, interviews and user tests resulted in finding a large number of possible actions to take when constructing a non-profit crowdfunding platform. The measures were summarized and condensed into a collection of recommendations and considerations to take when designing such a platform to increase donor retention. The thesis also identified that crowdfunding components can make a charity website appear more transparent and innovative. Additionally, the thesis found that many donors continue to donate based on their initial conviction. Where the ability to provide proof of where the donations end up and ability to appear transparent were the most cited reasons for deciding to support an organization.