It is a toolbox for Sequential Probability Ratio Tests (SPRT), Wald (1945) doi:10.2134/agronj1947.00021962003900070011x . SPRTs are applied to the data during the sampling process, ideally after each observation. At any stage, the test will return a decision to either continue sampling or terminate and accept one of the specified hypotheses. The seq_ttest() function performs one-sample, two-sample, and paired t-tests for testing one- and two-sided hypotheses (Schnuerch & Erdfelder (2019) doi:10.1037/met0000234 ). The seq_anova() function allows to perform a sequential one-way fixed effects ANOVA (Steinhilber et al. (2023) doi:10.31234/osf.io/m64ne ). Learn more about the package by using vignettes "browseVignettes(package = "sprtt")" or go to the website https://meikesteinhilber.github.io/sprtt/.