An ethylene-based polymer, which is a low density polyethylene (LDPE), obtained by free radical polymerization of ethylene, and wherein the LDPE has a GPC parameter “LSP” less than 1.60.An ethylene-based polymer that comprises the following features: a) at least 0.1 amyl groups per 1000 total carbon atoms; b) a melt index of 0.01 to 0.3; c) a z-average molecular weight of Mz (conv.) of greater than 350,000 g/mol and less than 425,000 g/mol; d) a gpcBR value from 1.50 to 2.05, and e) a MWD(conv) [Mw(conv)/Mn(conv)] from 6 to 9. An ethylene-based polymer that comprises the following features: a) at least 0.1 amyl groups per 1000 total carbon atoms; b) a melt viscosity ratio (V0.1/V100), at 190° C., greater than, or equal to, 58; c) a melt viscosity at 0.1 rad/s, 190° C., greater than, or equal to, 40,000 Pa·s, and d) a gpcBR value from 1.50 to 2.25.