Text.Proper capitalizes the first letter of each word and lowercases the rest. Available in Excel (Power Query), Power BI Desktop, and Power BI Service.
If you want to clean up name or text columns so each word starts with a capital, this is the function you reach for. It takes a text value and hands back a tidy, proper-cased version.
Syntax of Text.Proper Function
Text.Proper(text as nullable text, optional culture as nullable text) as nullable text
where
text(required, nullable text). The text value you want to proper-case.culture(optional, nullable text). A culture code such as"en-US"that controls casing rules. Omit it for the default behavior.
Returns: the text with the first letter of each word capitalized and every other letter in lowercase. If text is null, it returns null.
In plain terms, you give it a string and it gives you back the same string with proper casing applied.
Example 1: Proper-case a simple name
Capitalize each word in a lowercase name.
Text.Proper("john smith")
Result: John Smith
Both words get their first letter capitalized.
Example 2: It lowercases existing caps, then rebuilds the case
Text.Proper("the QUICK bROWN fox")
Result: The Quick Brown Fox
It does not just touch the first letter. It lowercases every interior capital first, then capitalizes the first letter of each word. So QUICK becomes Quick and bROWN becomes Brown.
Example 3: It capitalizes after every apostrophe and hyphen
This is the gotcha to watch for.
Text.Proper("o'brien from new-york met mcdonald")
Result: O'Brien From New-York Met Mcdonald
The function treats any non-letter as a word boundary, so it capitalizes the letter right after each apostrophe and hyphen. That gives you O'Brien and New-York. And because the only break in mcdonald is at the start, you get Mcdonald, with a lowercase donald.
Example 4: Proper-case a Name column in a table
Proper-casing a whole column is the most common use of this function.
Say you have a Staff query with a FullName and a Dept column.
Here is the starting data:
| FullName | Dept |
|---|---|
| amir KHAN | finance |
| mary-jane WATSON | design |
| o’connor liam | support |
Now apply Text.Proper to the FullName column with Table.TransformColumns:
let
Source = Excel.CurrentWorkbook(){[Name="Staff"]}[Content],
Result = Table.TransformColumns(Source,{{"FullName",Text.Proper}})
in
Result
The result proper-cases every name and leaves Dept untouched:
| FullName | Dept |
|---|---|
| Amir Khan | finance |
| Mary-Jane Watson | design |
| O’Connor Liam | support |
The hyphen in Mary-Jane and the apostrophe in O'Connor both trigger a capital, same as Example 3.
Example 5: Null input returns null
Text.Proper(null)
Result: null
A null passes straight through, so you do not get an error on blank cells.
Things to keep in mind with Text.Proper
- It capitalizes after any non-letter, not just spaces. Apostrophes, hyphens, and digits all trigger a capital, which mangles names like
O'BrienandMcDonald(Example 3). To fix specific names, clean them up afterward withText.Replaceor a small custom function. - It flattens ALL-CAPS acronyms. Because it lowercases every letter it does not capitalize,
"USA"becomesUsaand"NASA report"becomesNasa Report. Protect acronyms with a separate replace step. - A number throws an error. Passing a non-text value like
42raisesExpression.Error: We cannot convert the value 42 to type Text.Convert it first withText.From. cultureis rarely needed. The default casing handles standard English text. Reach for it only when a locale capitalizes differently.
Performance and query folding
Against a foldable source such as SQL Server, a Text.Proper step usually does not fold, since most databases have no single equivalent. It runs locally instead. On Excel, CSV, or folder sources it always runs locally, which is fast for thousands of rows.
Common questions about Text.Proper
How do I keep names like McDonald and O’Brien correct?
Run Text.Proper first for the bulk of the work, then patch the exceptions with a replace step. A column-wide swap with Table.ReplaceValue, for example replacing Mcdonald with McDonald, fixes the known offenders. For many such names, a lookup table of corrections applied after the proper-case step is cleaner than one giant chain of replacements.
What is the difference between Text.Proper, Text.Upper, and Text.Lower?
Text.Proper capitalizes the first letter of each word and lowercases the rest. Text.Upper makes everything uppercase, and Text.Lower makes everything lowercase. To apply any of these across a plain list of values rather than a table column, wrap them in List.Transform.
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