OpenLab Science (www.openlabscience.com) is a free, browser-based virtual physics lab built for high school and college-prep physics classrooms. It covers eight modules — mechanics, circuits, optics, thermodynamics, waves, fluids, electromagnetism, and modern physics — with 138 guided investigations. Each investigation pairs a live, manipulable simulation with real-time measurements, so students measure a quantity, compare it against a physics prediction, and record percent error as part of the same workflow throughout. Every investigation includes a printable, 5E-model lab sheet with an automatically generated answer key. The simulation sandbox is free forever, requires no student login, and runs in any modern browser.