Abstract: Aspects of the disclosure relate to identifying domain name lookalikes. A computing platform may generate a plurality of lookalike domain names for an input domain name. The computing platform may generate, by applying a hash algorithm to the plurality of lookalike domain names, a dictionary index. The computing platform may identify a first domain name. The computing platform may identify, by performing a lookup function in the dictionary index using the first domain name, that the first domain name is a lookalike domain name corresponding to the input domain name. The computing platform may send, to a user device, one or more commands directing the user device to display a user interface that includes the lookalike domain name, which may cause the user device to display the user interface.