Stopping distance against speed
Pick each point from a scatter plot of speed and stopping distance.
Source: R datasets (cars)
Plot Digitizer
FigranUpload a graph image, mark two values on each axis, and click points to extract their data.
- Linear and log axes
- Auto-trace curves
- Image stays in your browser
Axes
X axis
Y axis
Points
Automatic extraction
Extraction mode
Result mode
Export
| Dataset | X | Y |
|---|---|---|
| cars | 3.99 | 2.0 |
| cars | 3.99 | 10.0 |
| cars | 7.00 | 4.0 |
| cars | 7.00 | 22.0 |
| cars | 8.00 | 16.0 |
| cars | 8.99 | 10.0 |
| cars | 10.00 | 18.0 |
| cars | 10.00 | 26.0 |
| cars | 10.00 | 34.0 |
| cars | 11.01 | 17.0 |
| cars | 11.01 | 28.0 |
| cars | 12.00 | 14.0 |
| cars | 12.00 | 20.0 |
| cars | 12.00 | 24.0 |
| cars | 12.00 | 28.0 |
| cars | 13.00 | 26.0 |
| cars | 13.00 | 34.0 |
| cars | 13.00 | 34.0 |
| cars | 13.00 | 46.0 |
| cars | 13.99 | 26.0 |
| cars | 13.99 | 36.0 |
| cars | 13.99 | 60.0 |
| cars | 13.99 | 80.0 |
| cars | 15.00 | 20.0 |
| cars | 15.00 | 26.0 |
| cars | 15.00 | 54.0 |
| cars | 16.01 | 32.0 |
| cars | 16.01 | 40.0 |
| cars | 17.00 | 32.0 |
| cars | 17.00 | 40.0 |
| cars | 17.00 | 50.0 |
| cars | 18.00 | 42.0 |
| cars | 18.00 | 56.0 |
| cars | 18.00 | 76.0 |
| cars | 18.00 | 84.0 |
| cars | 18.99 | 36.0 |
| cars | 18.99 | 46.0 |
| cars | 18.99 | 68.0 |
| cars | 20.00 | 32.0 |
| cars | 20.00 | 48.0 |
| cars | 20.00 | 52.0 |
| cars | 20.00 | 56.0 |
| cars | 20.00 | 64.0 |
| cars | 22.00 | 66.0 |
| cars | 23.00 | 54.0 |
| cars | 23.99 | 70.0 |
| cars | 23.99 | 92.0 |
| cars | 23.99 | 93.1 |
| cars | 23.99 | 120.0 |
| cars | 25.00 | 85.0 |
Plot digitizer examples: scatter, bar, log-axis and survival graphs
Tooth growth with error bars
Digitize group means and error-bar caps.
Source: R datasets (ToothGrowth)
Dose response on a log X axis
Compare treated and untreated reaction rates.
Source: R datasets (Puromycin)
Kaplan–Meier lung cancer survival by sex
Trace survival curves from patient data.
Source: R survival (lung)
Annual Nile flow time series
Extract a line from annual observations.
Source: R datasets (Nile)
Chick weight by diet (rotated scan)
A tilted, scanned figure — four-point calibration corrects the rotation.
Source: R datasets (ChickWeight)
How to digitize a graph
1Upload an image
Add an image to the plot digitizer by choosing a file, dropping it on the workspace or pasting a screenshot.
2Calibrate the axes
Click two known positions on each axis and enter their values.
3Automatic extraction for curves and markers
Click points manually or pick a color and extract a curve or markers.
4Copy or download the data
Review the points and export a CSV or copy a tab-separated table.
Extracting data from published figures for meta-analysis
1To extract data from a figure, first calibrate its axes using known values.
2The plot digitizer shows per-pixel resolution; image resolution and click placement limit precision.
3For bars, distinguish the bar top from error-bar caps and consult the original caption before interpreting them.
Record the source figure and check extracted coordinates independently. Digitized Kaplan–Meier coordinates can support reconstruction methods such as Guyot et al. (2012).
Plot digitizer FAQ
How accurate is graph digitization?
Accuracy depends on image resolution and calibration. Check the displayed per-pixel resolution and compare repeated extractions. Drevon and colleagues studied the reliability and validity of digitized graph data. Drevon et al. (2017).
Can it read log scale axes?
Yes. In the plot digitizer, select Log10 independently for each axis and enter positive calibration values.
How do I extract data from a bar chart with error bars?
Select Bar chart, calibrate Y, and click the bar top and error-bar caps. Consult the original caption to determine whether the bars represent SD, SEM, or confidence intervals.
Can it trace a curve automatically?
Yes. Pick a color and use Line or Markers; overlapping or similarly colored marks may require manual correction.
Can I extract data from a PDF graph?
Take a screenshot or copy the image and paste it here. Enlarge a vector figure before taking the screenshot for better resolution.
Is my image uploaded?
No. The plot digitizer processes images in your browser and does not upload them.
How is this different from WebPlotDigitizer?
WebPlotDigitizer supports additional graph types. This page focuses on XY and bar graphs, log axes and examples with source data.
What should I report when I use digitized data?
Report the plot digitizer used and the source figure, and describe how you checked the extracted coordinates.
Digitize your graph
Extract coordinates with the plot digitizer and download a CSV.