Perplexity of t-SNE Use this option to specify Perplexity for the t-SNE algorithms. The perplexity is related to the number of nearest neighbors that is used in other manifold learning algorithms. Different values can result in significantly different results. Larger data sets usually require a larger perplexity. Consider selecting a value between 5 and 50. By default, the perplexity is set to 30. To Specify the Perplexity: Enter the desired value in the text box.