Home / Exercise guides / Bicep Curl rep counter

Bicep Curl Rep Counter

Stop counting in your head. Point your phone at yourself and every full-range bicep curl counts itself — sets, reps, and PRs logged automatically while you train your biceps, with forearms assisting. Free, in your browser, no account needed.

▶  Start Counting Free
GOODREPSLIVE
VISION ▾FORM
DOWN
CURLS7/ 10
The live screen, in miniature — the moving skeleton is the app’s real bicep curl demo pose (front view), with the rep counter, form bar, and phase dot exactly as they run in a session. All processed on-device.
Straight From The App

HOW TO DO A PROPER BICEP CURL

Setup  Stand facing the camera, a weight in each hand, arms hanging straight, palms forward.

  1. Curl the weights up toward your shoulders, elbows pinned to your sides.
  2. Squeeze at the top, then lower under control until your arms are fully straight.
  3. Don't swing — only your forearms move.
Form cue: Extend fully

This is the same instruction sheet you’ll find on the ⓘ panel inside the app — with an animated demo next to it.

How The Counting Works

HANDS-FREE IN THREE STEPS

1

Prop your phone and get in frame

Set your phone at roughly torso height and stand facing the camera. The built-in camera test confirms your lighting, distance, and angle with live green checks before you start.

2

The AI locks a 17-point skeleton on you

GoodReps measures your elbow angle (shoulder → elbow → wrist) in real time, entirely on your device. No wearables, no clickers. A pair of dumbbells — or anything with a bit of weight; log it and track PRs.

3

Just work — the counter does the counting

A rep banks at the bottom (~45°) and re-arms when you return toward ~155°. Half reps don’t count, and after 3 clean reps it calibrates to your personal range of motion.

Under The Hood

WHAT MAKES A REP COUNT

Form Still Matters

COMMON BICEP CURL MISTAKES

Swinging the weight up

If your torso rocks, your hips are curling — not your biceps. Pin your elbows to your sides and let the forearm do all the travel.

Never straightening the arm

Stopping halfway down keeps constant tension off the muscle's full range. Let the arm reach full extension before the next rep — the counter checks for it.

Rushing the lowering half

Dropping the weight wastes the best part of the rep. Take two beats on the way down; your biceps grow on the negative too.

Wrists curling inward

Bent wrists shift the load to your forearms. Keep them neutral, like you're holding a tray handle.

Your Data

PRIVATE BY DESIGN

Rep counting runs entirely on your device — your camera feed is never uploaded.

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.

FAQ

QUESTIONS, ANSWERED

Do I need dumbbells to count bicep curls?

Any weight works — dumbbells, resistance bands, even a loaded backpack. Log whatever you're lifting and the app tracks your PRs across sessions.

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.

Keep Going

RELATED GUIDES

▶  Try GOODREPS Free In Your Browser

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.