Read the numbers off any graph

Got a chart in a scanned PDF, a textbook, or an old code book — but not the data behind it? Trace it here and get the numbers back. No sign-up, no upload: everything runs in your browser.

Load a picture of the graph (drop it here, paste with Ctrl-V, or the button above).
Calibrate the axes — click two known points on each axis and type their values.
Trace the line, then Export the points as JSON or a ready-to-use function.

Drop an image here to start, or Load image… from the toolbar.

New here? Read how to digitize a graph.

1 · Axis calibration

Click Set, then click the point on the chart, then type its axis value. Two points per axis.

Snap to detected gridlines —

X horizontal axis

X₁ —

X₂ —

Y vertical axis

Y₁ —

Y₂ —

load an image to begin

2 · Curves / contours

Snap points to the nearest line

In Trace mode, click along the active (highlighted) curve — clicks snap onto the line.

3 · Fit & verify 1D

Fit deg

Overlay fitted curve on image (verification)

4 · Read a value

x =

Enter an x to read y straight off the fitted curve — no clicking needed.

Get your data

Preview — the numbers you'll get. Tab-separated, pastes straight into a spreadsheet.

Your images & data never leave your browser. A free Sutranet tool — privacy.