AI Form Check for Squat, Bench Press & Deadlift

Form Detective is a free AI-powered lifting form checker. Upload a phone video of your squat, bench press or deadlift and get a rep-by-rep written report plus a true 3D skeleton replay — built on YOLO pose detection, ViTPose and VideoPose3D.

What it detects

  • Squat depth, knee cave (valgus), butt wink, forward lean and heel lift
  • Bench press bar path drift, elbow flare, uneven lockout and shoulder position
  • Deadlift spine rounding, hip shift, bar path away from body and lockout asymmetry

Body Map — track risk and fatigue per muscle

An interactive anatomical Body Map lets you log injury risk and training fatigue independently for each muscle group, with severity from mild to severe. Risks detected from your video analyses flow in automatically.

Personalized warmup and cooldown

Each lift has a hand-curated baseline warmup and cooldown. On top of that, recurring issues from your last 60 days of video analyses (knee valgus, forward lean, butt wink, bar path drift, etc.) layer in extra mobility drills targeted at the muscles driving those errors.

AI coach chat with memory

Ask follow-up questions in chat. The coach has context on your active body risks, your current fatigue, and the form errors that keep showing up across your sessions, so its cues are specific to you instead of generic.

Frequently asked questions

How does AI form check work?

You upload a short video of your lift. Form Detective runs pose estimation (YOLO + ViTPose) and reconstructs a true 3D skeleton with VideoPose3D. It then analyzes each rep for common form errors and returns a written report plus a 3D replay you can scrub through.

Which lifts are supported?

Squat, bench press and deadlift are fully supported with exercise-specific error detection — depth, knee cave, butt wink, bar path drift, elbow flare, lockout asymmetry, and more.

Is it free?

Yes — every account gets free daily form checks. Heavier usage is covered by a low-cost credit pack. No subscription required.

Does it work with phone video?

Yes. A normal side-on phone video at 30fps is enough. The 3D reconstruction runs server-side on GPU, so you don't need a special camera or depth sensor.

Is squat depth detected automatically?

Yes. Hip-crease vs knee position is computed from the 3D skeleton on every rep, so depth is reported objectively rather than by eyeballing the video.

What happens to my video after analysis?

Uploaded videos auto-delete one hour after processing. Only the numeric analysis (joint angles, error tags, scores) is retained for your history.

Can the AI coach remember my previous sessions?

Yes. Recurring issues from your last 60 days of analyses are surfaced to the coach chat and used to layer extra warmup and cooldown drills into your routine.

Learn more

  • Squat form check
  • Bench press form check
  • Deadlift form check
  • How the 3D analysis works
  • Lifting form blog