Replace Blank Strings with Null in Power Query M

Converts empty-string values in a table to true nulls, which Power Query treats differently from blanks.

Data CleaningBeginnerblanknullempty stringcleaning

Power Query M code

let
    Source = YourTable,
    Replaced = Table.ReplaceValue(Source, "", null, Replacer.ReplaceValue, Table.ColumnNames(Source))
in
    Replaced

Notes

Run this before type conversion - empty strings often fail to convert to number or date, while null converts cleanly.

Requirements

A table where missing values are stored as empty strings instead of null.

How to use this snippet

In Power BI Desktop, choose Transform data to open Power Query, then open the Advanced Editor on a query (or start from a blank query).
Paste the snippet and replace the placeholder names (tables, columns, file paths) with your own. Check the requirements above first.
Run it through the Power Query M Formatter to tidy the layout.

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