100% local · MP4 / WebM / MOV · Chrome, Edge, Safari

Frame-precise movement analysis. Right in your browser.

StepScope is the analysis tool for dance teachers, choreographers, and movement coaches. Drop markers, group by topic, record commentary, export a polished highlight reel — all locally, no uploads, no accounts.

Start a new analysis See how it works

Marker · Topic · Reel

The topic-based workflow

Stop scrubbing through hours of footage. Mark the moments that matter, group them by theme, record commentary per topic — out comes a polished highlight reel.

Mark
Hit `M` while the video plays. A marker lands at the current frame with ±2.5s of context.
Group
Ten coloured topics. Chord `M+1`…`M+9` tags the marker as you drop it. Slot 0 = untagged.
Record
Record audio commentary per topic plus live drawings. Three drawing lifetimes: Autofade, Keep, or Pause-only.

What else is in the box

Frame-precise stepping

30 / 60fps, requestVideoFrameCallback, exact frame-by-frame navigation.

Pose tracking

MediaPipe Pose Landmarker. Manual correction plus Web Worker-accelerated auto-tracking.

Audio-master replay

Three-track recording (audio + frame samples + drawings). Replay shows exactly what you saw — 1:1.

Side-by-side comparison

Two videos in sync, beat-aligned by BPM markers.

Reel export

FFmpeg.wasm renders your topic reel to MP4 — fully offline.

Local, always

Videos never leave your machine. The File System Access API remembers your files between sessions.

Frequently asked

Will my videos be uploaded?

No. Everything runs in your browser. No servers, no account, no cookies.

Which browsers work?

Chrome and Edge work best (File System Access). Safari and Firefox work via drag-and-drop, without persistent file linking.

What does StepScope cost?

Nothing. It's a hobby project, no business model.

Which video formats?

MP4 (H.264/H.265), WebM, MOV. Recordings at 30 or 60fps give the best results.

How large can videos be?

Limited by your RAM — 1–2 GB clips work without issues.