KalaSudha online tanpura is a browser based digital tanpura application developed by KalaSudha Ltd., a social enterprise focused on Indian classical music, dance, and arts. The tool generates a continuous drone sound, a fundamental accompaniment in Indian classical music, directly within a web browser. It is designed to provide a practice drone for musicians and vocalists without requiring any account creation or software installation. The application offers extensive customization of the tanpura sound. Users can set the tonic note (Sa) by selecting a harmonium key or entering a kattai number, and choose between lower or higher registers. Additional controls include selecting the first string (Pa, Ma, Ni, or Sa), adjusting the number of strings from four to six, and setting the time interval between plucks. The tool also allows users to modify the jawari (the characteristic buzzing timbre), simulate different room acoustics, and independently balance the volume of each string. The default practice drone is set to Sa at 138.6 Hz with a 6 second cycle. Typical use cases include vocal practice, instrumental rehearsal, and listening to a consistent drone for tuning or meditation. The workflow involves opening the webpage, configuring the desired pitch and string settings, and then playing the drone while practicing or performing alongside it. The application is intended for use on current versions of Chrome, Safari, Edge, and Firefox; it will not function on unsupported or outdated browsers. The platform is part of a larger KalaSudha ecosystem that also features artist profiles, stylistic traditions, instruments, albums, videos, articles, events, and educational courses related to Indian classical arts.