The share of rows where a column is empty — a jump usually means an upstream field stopped being populated.
Reviewed by Francisco Ferreira ·
The null rate of a column is the percentage of rows where its value is missing. Some nullness is expected; what matters is change. When a column that's normally 2% null suddenly becomes 40% null, something upstream broke — a form field stopped saving, a join started missing, or an API began returning blanks.
Null spikes are sneaky because totals still compute. Averages quietly shift, counts of 'completed' records drop, and segmentation silently loses people — all without a single error message to warn you that the column went hollow.
Tabkeel tracks each column's baseline null rate and flags the spike, pointing you at the exact column and the moment it changed.