Null & Missingness Heatmap Learn more

See missing values by column (and by segment) so you can spot broken fields fast. Runs locally in your browser.

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CSV / TSV / Excel (XLSX/XLS)

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Delimiter Max rows to scan

Options

Group-by lets you spot segments where missingness suddenly spikes (optional).

Group by

Top groups Columns in heatmap

Run

Computes missingness (blank / null / NaN) per column. Download a report if needed.

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Missing means: empty string, whitespace-only, null, undefined, or NaN.

Column summary

Sorted by highest missingness.

Rows:— Columns:—

Column	Missing	Missing %	Preview

How to read results

High missing % usually means an upstream export/pipeline dropped a field or changed a join.

Sudden spikes by segment often point to a filter, timezone boundary, or key mismatch.

If this affects a key metric, consider reconciling totals and checking duplicates next.

Segment heatmap (optional)

If you choose a group-by column, this highlights where missingness concentrates.

No group-by selected

Null & Missingness Heatmap