An algorithm for solving a class of linear variable-order fractional differential equations (FDEs) numerically is presented in this paper. We utilized a combination of Caputo fractional derivatives with the Haar wavelet collocation method (HWCM) to numerically solve linear variable order FDEs. Examples are provided to demonstrate the precision of the suggested method. Some examples are provided to demonstrate the effectiveness and precision of HWCM. Additionally, maximum absolute error and mean square root error of each test problem are computed for various numbers of collocation points to demonstrate the validity and application of the suggested method. A comparison of exact and approximative solutions is shown in the figure for different numbers of collocation points.