Online bingo sites use random number generators (RNGs) to deliver completely random results. Most operators submit their RNGs to third-party testing labs. After passing testing, they can display the relevant lab’s seal on their homepage. For example, you may find a seal for eCOGRA—one of the premier labs—at the bottom of a bingo site’s homepage. In short, you can play without fear when choosing operators that have undergone and passed third-party testing.