Read the scale
Confirm baseline, intervals, units, and breaks.
Convert a chart image to a reviewable data table
Chart OCR reconstructs visible labels and plotted values into a table for review. It works best when values are printed on the chart; estimating values from an unlabeled axis remains approximate and must be checked against the original scale.
Your chart data is ready to review
N/Alocal review signal
0 pages0 words0 characters0 ms
Values printed on the chart are stronger than values inferred from a scale. Mark estimates and verify every series against the legend.
Make the visual encoding inspectable as data
The chart supplies categories, series, and a scale. The result separates those elements into cells so the reviewer can see which values were read directly and which remain uncertain.
- Confirm the chart type, units, scale, and zero baseline.
- Match every legend entry to the correct series.
- Treat values inferred between tick marks as estimates.
Reconstruct chart evidence before interpreting it
Use this tool when a chart contains data labels or a clear axis that can support a transparent reconstruction. Title, units, axes, legend, categories, and values all contribute to the table. Removing one can change the meaning of every number.
Map the series
Match color, symbol, or pattern to its legend label.
Review the cells
Separate printed values from visual estimates.
Know when a chart supports exact values and when it does not
Data labels can support direct transcription. Unlabeled points between grid lines support only estimates, especially after resizing or perspective distortion.
Include the legend and axes
A tight crop can remove units, series names, the zero baseline, or scale breaks.
Avoid perspective
A photographed chart should be square to the page so the scale remains consistent.
Separate labels from estimates
Keep printed values distinct from values inferred between grid lines.
Check stacked values
Confirm whether labels describe each segment, the cumulative height, or the total.
Watch truncated axes
A nonzero baseline can exaggerate small differences, so preserve and record the displayed minimum before reconstructing any value.
Use chart OCR for transparent reconstruction, not statistical conclusions
Apply the cell-checking approach from A Field-First OCR Workflow for Receipts, Invoices, and Tables.
For structured values and source checking, continue with the table and visual-data review guides.
Best for
Simple bar, line, and pie charts with visible labels, legends, units, or data values.
Not designed for
Interpreting causation, validating statistics, or recovering exact unlabeled values from decorative charts.
Review first
Axis scale, units, legend mapping, stacked segments, negative values, and inferred points.
Chart extraction questions
Can the tool recover exact values from any chart?
No. Exact recovery requires visible labels or a sufficiently clear scale. Otherwise the output is an estimate. Read the extraction limits.
Does it understand what the chart proves?
No. It reconstructs visible data and labels; interpretation, causation, and statistical validity remain separate tasks. Choose the right review level.