Among them: What are your goals? Are you doing this just to chat about your ethnic makeup? Do you want to find relatives through DNA matches so you can learn more about your genealogy? Are you adopted and looking for your birth family?
It’s important to think about what you’re trying to accomplish. The information provided by the four major testing companies, and the ease of use, varies a bit. I recently made a chart of my total number of DNA matches at the major four sites. At Ancestry.com, I have 65,000 matches, while my late mother has 112,000, so it may be a generational thing. At MyHeritage, I have 13,000, while at FamilyTreeDNA I have 8,700 in the autosomal test (FamilyFinder) area. At 23andMe, you’re only given access to your top 1,500 matches. It is my least favorite site because of difficult steps and because I have had the least amount of communication with the people I match with. If you really want to see the most number of matches, Ancestry.com has to be used. For Ancestry.com and 23andMe, you must take their tests (both spit tests) because you can’t copy your DNA into those sites. You can copy your DNA from either of them to FamilyTreeDNA or MyHeritage, both mouth swab tests.