OpenJump measures athletic jumps from recorded or imported video. Select takeoff and landing frame by frame; calculations use the video's real presentation timestamps rather than its nominal frame rate. • Six protocols: countermovement jump (CMJ), squat jump (SJ), Abalakov, unilateral jump, drop jump and standing horizontal jump. • Jump height, flight time, takeoff velocity and protocol-specific metrics; calibrated horizontal distance. • Athlete profiles, teams, local history, progress and comparisons. • Experimental video Encoder: scale calibration, visual tracking, repetition analysis, velocity and trajectory charts, and trajectory-video export. • Manual backups and user-initiated JSON/CSV exports. • Configurable units, light/dark appearance and eight interface languages. Analysis and saved measurements stay on your device. No accounts, ads, automatic analytics or Internet permission. Sharing, exports, backups and support email require your action; destination applications may transfer those copies. Manual backup JSON is not encrypted. Results depend on video quality, viewpoint, calibration and event selection. Encoder is experimental and has not been validated against a physical encoder. OpenJump is not a medical or clinically validated device. Save an analysis before leaving it: unsaved work does not survive process death.