Real motion detection that locks bounding boxes, crosshair markers, and coordinate labels onto whatever moves in your footage.
How to use it
- Open the editor from this page — it loads a demo clip with the tracker already running — then drop in your own footage. The tracker feeds on motion, so it needs video, not a still.
- Tune the detection: raise the threshold to ignore small movement, add noise reduction to calm flicker, and cap how many blobs it follows.
- Pick the overlay color, set smoothing so the boxes glide instead of jitter, press play to watch it track, then export an MP4.
What the blob tracker actually does
The tracker compares each frame of your video against the previous one, groups the pixels that changed into connected regions, and filters out the specks. Those regions are the blobs. Each one gets a stable identity: the tracker matches this frame’s detections against the blobs it was already following, so a box stays locked to its subject instead of flickering in and out, and a smoothing filter turns raw per-frame detections into paths that glide. On top of each blob it draws the machine-vision overlay: a bounding box, a crosshair at the centre, and a label reading out the blob’s id and live coordinates.
That overlay is the look that came out of TouchDesigner installations and took over music videos and social edits: footage annotated by software that is watching it. The same Tracking effect ships in the Modulate editor with the rest of its surface: color and edge detection modes alongside motion, per-blob color palettes, curved and animated connection styles, a full set of marker shapes and label formats, and the ability to host other effects inside the tracked regions, so a blur or pixelation follows the subject automatically.
Common questions
Is the blob tracker free?
Yes. This page opens the full Modulate editor, free with no signup, with the effect already set up. Anonymous exports run up to 5 seconds at 1080px with a small watermark; a free account removes the watermark and raises exports to 1920px and 30 seconds, and Pro raises the caps to 4K and 5 minutes.
Why does it need video?
The tracker finds blobs by detecting motion between frames. A still image has no motion, so there is nothing to detect and nothing to track. Any clip with a moving subject works: people, traffic, animals, particles.
Is this the same as blob tracking in TouchDesigner?
Same technique, different route. TouchDesigner builds blob tracking from a node network, which is where most tutorials point. This tool runs the detect-group-track pipeline directly in your browser: drop in a clip, tune a few controls, export.
Can it blur or pixelate whatever it tracks?
Yes: the Tracking effect can host other effects inside the tracked regions, so a pixelation or blur follows each subject automatically, the classic auto-censor. The page opens with the overlay look set up; add a region effect in the editor to censor instead of annotate.
Are my files uploaded to a server?
No. The motion analysis and the overlay both run in your browser. Your footage never leaves your computer unless you save it to a Modulate project yourself.
Go deeper
Blob tracking
Blob tracking detects distinct regions of movement in video, called blobs, and follows each one from frame to frame, drawing bounding boxes, crosshair markers, and coordinate labels around them. The result is the machine-vision look: footage annotated by software that is watching it. Originally a computer-vision technique for counting and following objects, it has crossed over into music videos, concert visuals, and social edits as an aesthetic in its own right.
Datamoshing
Datamoshing is a glitch technique that breaks the motion side of video compression: the decoder keeps applying fresh motion to stale pixels because the clean keyframes that would correct them are gone. Moving subjects smear into blocky trails, stopped motion keeps flowing, and the image only recovers when a new keyframe finally lands. It is the most cinematic glitch there is, because it is made of the video’s own movement.
Pixel sorting
Pixel sorting rearranges the actual pixels of an image along straight lines: contiguous runs of pixels that pass a brightness test are reordered by brightness, hue, or saturation, so each run becomes a smooth ramp and the image appears to bleed into streaks of light. Nothing is added and nothing is lost, every pixel survives in a new position, which is why sorted images keep an unmistakably photographic grain inside the abstraction.
There's more where this came from
The full editor lets you use every effect together, over video, text, 3D, and shapes. Free, no signup, nothing to install — it opens with this effect already set up.
Open the editor