REST is a MATLAB-based toolkit for processing resting-state functional magnetic resonance imaging (RS-fMRI) data. It provides a user-friendly graphical interface (GUI) and integrates various analytical methods for RS-fMRI data, including functional connectivity analysis, regional homogeneity (ReHo), and amplitude of low-frequency fluctuations (ALFF). REST supports data preprocessing with SPM or AFNI, and offers additional functions such as DICOM sorting, linear trend removal, bandpass filtering, and statistical analysis. The toolkit is open-source and freely available at http://www.restfmri.net. REST enables the analysis of RS-fMRI data by calculating functional connectivity using Pearson correlation, ReHo using Kendall's coefficient of concordance, and ALFF using power spectrum density. It also includes fractional ALFF (fALFF), which is a normalized version of ALFF. REST supports batch processing and is compatible with MATLAB versions 6.5 and higher. It is designed to be user-friendly for both basic and clinical neuroscientists. REST has been used in various studies to analyze RS-fMRI data, including investigations into brain disorders such as ADHD, schizophrenia, depression, Alzheimer's disease, and Parkinson's disease. The toolkit provides a framework for implementing additional methods and is widely used in the field of resting-state fMRI research. REST is freely available and has been cited in numerous publications. It is an important tool for the analysis of resting-state fMRI data, offering a comprehensive set of functions for both data processing and statistical analysis.REST is a MATLAB-based toolkit for processing resting-state functional magnetic resonance imaging (RS-fMRI) data. It provides a user-friendly graphical interface (GUI) and integrates various analytical methods for RS-fMRI data, including functional connectivity analysis, regional homogeneity (ReHo), and amplitude of low-frequency fluctuations (ALFF). REST supports data preprocessing with SPM or AFNI, and offers additional functions such as DICOM sorting, linear trend removal, bandpass filtering, and statistical analysis. The toolkit is open-source and freely available at http://www.restfmri.net. REST enables the analysis of RS-fMRI data by calculating functional connectivity using Pearson correlation, ReHo using Kendall's coefficient of concordance, and ALFF using power spectrum density. It also includes fractional ALFF (fALFF), which is a normalized version of ALFF. REST supports batch processing and is compatible with MATLAB versions 6.5 and higher. It is designed to be user-friendly for both basic and clinical neuroscientists. REST has been used in various studies to analyze RS-fMRI data, including investigations into brain disorders such as ADHD, schizophrenia, depression, Alzheimer's disease, and Parkinson's disease. The toolkit provides a framework for implementing additional methods and is widely used in the field of resting-state fMRI research. REST is freely available and has been cited in numerous publications. It is an important tool for the analysis of resting-state fMRI data, offering a comprehensive set of functions for both data processing and statistical analysis.