Table.ReplaceValue()

Table.ReplaceValue() finds and replaces a value across one or more columns of a table — the function behind Transform > Replace Values in the Editor.

Table.ReplaceValue(
    table as table,
    oldValue as any,
    newValue as any,
    replacer as function,
    columnsToSearch as list
) as table

Basic Example

#"Replaced Value" = Table.ReplaceValue(
    Source, "N/A", null, Replacer.ReplaceValue, {"Amount"}
)

Amount        Amount
1200          1200
N/A     ->    null      <- replaced
850           850

The Column List Is Not Optional in Practice

The last argument, columnsToSearch, is a required list of column names — the replace only runs against the columns named there, not the whole table. This is the single most common source of confusion with this function.

#"Replaced Value" = Table.ReplaceValue(
    Source, "N/A", null, Replacer.ReplaceValue, {"Amount"}
)

If the same placeholder also appears in a Quantity column that wasn't listed, it's left completely untouched — no error, no warning, just a silent miss in a column nobody remembered to add to the list.

Fix: explicitly list every column that could contain the value.

#"Replaced Value" = Table.ReplaceValue(
    Source, "N/A", null, Replacer.ReplaceValue, {"Amount", "Quantity", "Discount"}
)

Replacer.ReplaceValue vs. Replacer.ReplaceText

The replacer argument controls match behavior, and the two most common options behave differently:

-- Exact match: only replaces a cell that IS "N/A"
Table.ReplaceValue(Source, "N/A", "", Replacer.ReplaceValue, {"Notes"})

-- Substring match: replaces "N/A" wherever it appears within the text
Table.ReplaceValue(Source, "N/A", "", Replacer.ReplaceText, {"Notes"})

Using Replacer.ReplaceValue on a Notes column expecting it to strip "N/A" out of a longer sentence like "Status: N/A for now" won't do anything — the cell isn't exactly "N/A", just contains it. That case needs Replacer.ReplaceText.

Common Mistakes

Assuming It Searches the Whole Table

As covered above — a column left off the list is silently skipped, not searched-and-found-nothing. Always double-check the column list against every place the value could actually appear.

Using ReplaceValue When ReplaceText Was Needed

Expecting an exact-match replacer to catch a substring inside a longer text value — it won't, and it fails silently rather than erroring, since the operation itself is still valid, it just never matches.

Replacing Text and Non-Text Values With the Same Call

Replacer.ReplaceText only works on columns typed as Text — pointing it at a numeric or date column throws a type error, since there's no "substring" concept for those types. Use Replacer.ReplaceValue for anything that isn't text.

Not Checking for Multiple Placeholder Variants

A source with "N/A" in some rows often has "n/a", "-", or a blank string elsewhere too, from different people entering data inconsistently. One Table.ReplaceValue() call only catches the exact variant it was given — checking for the full set of placeholders actually present (via a quick Table.Distinct() on the column) avoids fixing only part of the problem.

Next Steps

• M Language
• M Function Reference
• Transformations
• Text.Contains() & Text.Replace() — the substring-level version of the same problem

Cleaning up placeholder values as part of a broader type-conversion error? See We Couldn't Convert to Number (or Date) for the fuller pattern, including locale mismatches and hidden whitespace.