What primer is better, Kilz or Zinsser?

What primer is better, Kilz or Zinsser, depends on specific use, but overall most professional painters rate Zinsser slightly better than Kilz for versatility, adhesion, and stain blocking, though Kilz offers better value. Both brands make good primers at different price points. Kilz, owned by Masterchem, is known for affordable primers like Kilz Original oil-based for severe stains, Kilz 2 all-purpose water-based, and Kilz Mold and Mildew, costing 10 to 25 dollars per gallon less than Zinsser, making it popular for budget jobs, rentals, and large areas. Zinsser, owned by Rust-Oleum, offers Bulls Eye 1-2-3 water-based all-purpose primer, Cover Stain oil-based for tough stains, and BIN shellac-based primer which is considered industry best for blocking smoke, pet odor, nicotine, and severe water stains. In head-to-head tests, Zinsser BIN outperforms Kilz Original for odor and stain sealing, and Bulls Eye 1-2-3 adheres better to glossy surfaces without sanding than Kilz 2. Kilz Original is comparable to Zinsser Cover Stain for stain blocking but has stronger odor. For new drywall, both work, but Zinsser adheres better. For mold, both have mold-resistant versions. If you want cheapest adequate primer for drywall, Kilz 2 is fine. If you want best performance for difficult surfaces, stains, or glossy cabinets, Zinsser is better and worth extra cost. Many pros keep both, using Kilz for cheap jobs and Zinsser BIN for tough problems.