Box Jump Form Check
Wondering if your box jump is solid? Prop up your phone — GOODREPS watches your knee angle (hip → knee → ankle) live and scores every rep while you train your quads and glutes, with calves and core assisting. Free in your browser today; coming to Google Play and the App Store.
Coming to Google Play & the App Store▶ Try The Form Check
LIVEHOW TO DO A PROPER BOX JUMP
Setup Stand facing a sturdy box, side-on to the camera.
- Dip into a quarter-squat and swing your arms.
- Jump onto the box, landing soft with your hips fully open.
- Stand tall, then step back down.
Same sheet as the ⓘ panel in the app — animated demo included.
THREE STEPS TO A SCORED BOX JUMP
Prop your phone and get in frame
Phone at roughly torso height, set up side-on to the camera. A quick camera test checks lighting, distance, and angle before you start.
The camera locks a 17-point skeleton on you
GOODREPS measures your knee angle (hip → knee → ankle) on-device — no wearables. A sturdy box or platform at a height you can stick softly.
Move — and watch the form bar
The bar fills from ~170° toward ~115° at the bottom. Cut range short and it tells you; full ROM is what counts.
WHAT THE CAMERA WATCHES
- The explosive hip extension into the jump.
- A soft, quiet landing with knees tracking over toes.
- Standing tall on the box to finish before resetting.
COMMON BOX JUMP MISTAKES
Landing loud and stiff
Absorb with hips and knees. Noise means you are pounding cartilage.
Knees caving on landing
Knees track over mid-foot. Soft knees, strong hips.
Box too high for honest reps
Pride heights create ugly landings. Lower the box; own the landing.
Jumping down carelessly
Step down when fatigued. The landing off the box is another risk.
PRIVATE BY DESIGN
Pose detection runs in your browser via TensorFlow.js. Camera frames are analyzed in real time and immediately discarded — nothing is recorded, nothing leaves your phone, and we never see them. Sign-in is optional; skip it and everything stays local.
QUESTIONS, ANSWERED
Do I need any equipment to check my box jump form?
Just your phone for most variations. Add free weights when the pattern is clean — the app still scores the movement either way.
Does it work in a home gym or low light?
Run the built-in camera test first — it checks your lighting, distance, and angle with live green checks before you start. If a rep still slips through, manual counting is always one tap away.
Is my camera feed uploaded anywhere?
No. Pose detection runs entirely on your phone, in your browser. Frames are analyzed in real time and immediately discarded — nothing is recorded, nothing is uploaded.
RELATED GUIDES
Free forever — camera counting for all 60 exercises, no account needed. Pro (voice coaching, programs, depth-camera form checks) is $7/mo, $49/yr, or $99 once. No ads, ever.