VADAR (Volume Area Dihedral Angle Reporter) is a comprehensive web server designed for quantitative evaluation of protein structures. It accepts Protein Data Bank (PDB) formatted files or PDB accession numbers as input and calculates, identifies, graphs, reports, and evaluates over 30 key structural parameters for both individual residues and the entire protein. These parameters include excluded volume, accessible surface area, dihedral angles, secondary structure, hydrogen bonding, steric quality, and solvation free energy. VADAR is particularly useful for assessing protein structures determined by X-ray crystallography, NMR spectroscopy, 3D-threading, or homology modeling. The server provides detailed tables and graphical outputs, including scatter plots and line graphs, to help users identify both general and residue-specific problems within protein structures. VADAR is freely accessible at http://redpoll.pharmacy.ualberta.ca/vadar.VADAR (Volume Area Dihedral Angle Reporter) is a comprehensive web server designed for quantitative evaluation of protein structures. It accepts Protein Data Bank (PDB) formatted files or PDB accession numbers as input and calculates, identifies, graphs, reports, and evaluates over 30 key structural parameters for both individual residues and the entire protein. These parameters include excluded volume, accessible surface area, dihedral angles, secondary structure, hydrogen bonding, steric quality, and solvation free energy. VADAR is particularly useful for assessing protein structures determined by X-ray crystallography, NMR spectroscopy, 3D-threading, or homology modeling. The server provides detailed tables and graphical outputs, including scatter plots and line graphs, to help users identify both general and residue-specific problems within protein structures. VADAR is freely accessible at http://redpoll.pharmacy.ualberta.ca/vadar.