Today, everyday use of WiFi devices has become a necessity. There are several studies claiming the harmful effects of its rays on prokaryotes, yeasts, human and animal cells such as spermatozoids. The effects include DNA damage, oxidative stress, cellular apoptosis. However, the differences in how these rays affect cancer and non-cancer cells are still unknown. This research was aimed to find out if WiFi rays have the same influence on cancer and non-cancer cells. For the research, two different human cell lines were exposed by WiFi rays. The oxidative stress and DNA damage of each cell culture was studied with and without the influence of WiFi rays. Both these cell lines were seriously damaged by the rays; however, the non-cancer line showed a higher level of oxidative stress (measured by fluorescence microscopy) compared to the cancer cell line. In addition to this, it had more noticeable damage of DNA.