GiveWell

GiveWell is a charity evaluator that judges charities based on their impact. Its approach is different from those of other charity evaluators (except Giving What We Can), which tend to focus on measures such as the proportion of funds devoted to program expenses. For example, Charity Navigator, the most popular charity evaluator, rates charities on the four criteria of program expenses, administrative expenses, fundraising expenses, and fundraising efficiency. (Charity Navigator recognizes the shortcomings of its rating system and is developing a new set of criteria that takes into account programs' effectiveness in achieving their goals. . But ratings on program efficacy aren't yet available, and GiveWell and Giving What We Can remain the best sources for this information.) GiveWell also uses metrics such as disability-adjusted life years, which allow comparison between diverse programs.

GiveWell does not provide ratings for animal-welfare or existential-risk–reduction charities, though it may evaluate animal-welfare charities in the future.