plotdigitizer

Open image Load project

Drop, paste or open a chart imageor choose a bundled sample from the toolbar

1. Image

Deskew: pick two points on an axis line, then rotate. Do this before calibrating (rotation resets calibration and points).

Angle deg

2. Axes calibration

Mode

X scale Y scale

3. Datasets (manual mode)

Click to add a point to the active dataset, drag to adjust, right-click or Delete to remove. Alt+click a point also removes it.

snap to dark pixelradius

4. Auto extraction

pick a colour

Tolerance (Lab dE)

Open (remove specks) Close (fill gaps)

Mode

Step (px) Pick

limit to calibrated plot area

Brush radius restore

live preview

replace active dataset

5. Post-processing

X unit Y unit

remove outliers (k × MAD)

resample to uniform X grid, step

from to

Smoothing window order

Significant digits

6. Table

Dataset

7. Export

Format

8. Accuracy test (samples)

Applies the sample's known calibration, traces its series automatically and compares the result with the data the chart was drawn from.

show truth overlay