Video analyzer

Capture, calibrate, analyze. Load a clip, set the scale and origin, track by clicking the object to record its pixel position. You'll get a clean table in seconds and meters, then read velocity and acceleration off the fitted position graphs.

step 1

Load a clip

Choose video no clip loaded

Hints

Recommended: normal video at a constant 30 fps (60 fps also fine). For a drop, film from higher up so the fall lasts longer, and use good light and a high-contrast object so it stays sharp. Constant-rate frames are what this tool trusts.
iPhone Slo-mo is not recommended. It ramps in and out of slow motion instead of slowing evenly, which corrupts the frame timing and makes acceleration read wrong (often about 2.5x high with the sign flipped). It cannot be fully recovered after the fact. Use normal video instead, or trim to only the fully-slowed middle section.
If a clip will not decode, re-record in "Most Compatible" (H.264). Playback fps is detected for you on load.
Only true constant-rate high-speed footage (from a camera app that records a fixed fps, not Apple Slo-mo) should use Advanced > capture fps in step 2.
Do not move the camera after you start calibrating. Any camera move invalidates the scale and origin.

step 2

Workspace

Work down the rail in order: scale, origin, time zero, then track. Each blue button switches what your pointer does on the video.

Load a clip to begin.

t = -

jump frames:

1. Scale (pixels to meters)

A dashed bar appears on the video. Drag its ends onto an object of known length, then type that length. Drag the middle to move the whole bar.

length m

press Set scale bar to place it

2. Origin and axes

Click the point you want as (0, 0). For an incline, drag the x-axis arrowhead or type an angle.

angle deg

origin not set

3. Time zero

Step to where motion begins, then mark it.

t = 0 at 0.000 s

4. Track

auto advance after a click

scale: pending origin: pending time zero: 0.000 s

step 3

Tracked points

0 points

#	t (s)	x (m)	y (m)	x_px	y_px
no points yet

step 4

Graphs and interpretation

Position vs time for x and y. Pick the fit that matches the motion on each axis: Line means constant velocity (read the slope), Curve means constant acceleration (read 2a from the parabola). A projectile is Line on x, Curve on y. Something speeding up horizontally, or sliding down a tilted x axis, wants Curve on x. Click a point to drop it from the fits, click again to bring it back.

x fit: y fit:

no fit yet