No. The formatter is a lexer and layout engine written in JavaScript that runs inside this page, so your expression never leaves your browser and is never logged. You can verify it: open your browser devtools, switch to the Network tab, and format something — there are no requests. This matters more here than for most tools, because a DAX measure often encodes pricing, margin or compensation logic that should not be pasted into a third-party service.
What formatting style does it use?
The convention popularised by SQLBI and used by most published DAX: function arguments one per line when the call is too wide to fit, closing parenthesis aligned with the line that opened it, VAR declarations each on their own line, and RETURN on a line by itself. Function names and keywords are upper-cased while table and column names keep your exact capitalisation. A space before the opening parenthesis — SUM ( Sales[Amount] ) — is part of that style and can be switched off.
Could formatting change what my expression does?
It is designed so that it cannot, and it checks its own work. The tool never rewrites your logic — it splits the expression into tokens (names, literals, operators, comments) and only changes the whitespace between them. Before showing you anything it re-reads its own output and compares the token sequence against your input; if they differ in any way, it discards the result and shows an error instead. A refusal is rare, but it is deliberately preferred over output that looks fine and is subtly wrong.
Will short measures be exploded over several lines?
No. Anything that fits within the line width stays on one line, so Total = SUM ( Sales[Amount] ) is left alone. Only calls that exceed the width are broken up, and the width is adjustable — lower it to break more aggressively, raise it to keep more on one line.
Does it handle comments?
Yes. All three DAX comment forms are recognised: -- and // to end of line, and /* ... */ blocks. A line comment is always moved onto its own line, because leaving it mid-line would comment out whatever the formatter placed after it. If you would rather strip them, turn on "Strip comments".
My measure name contains a % or a space. Is that a problem?
No. Names such as Margin % =, Revenue $ = and Sales YTD % = are handled, as are quoted table names with spaces ( 'Date Table'[Date] ) and column names containing brackets or parentheses. If a regional setting means your model uses semicolons as argument separators — IF(x; 1; 0), common across Europe — that is supported too, and the semicolons are preserved rather than converted.
Why not just use the DAX editor in Power BI Desktop?
Power BI Desktop has no format command for measures; the formula bar keeps whatever you typed. This is why formatting DAX is a separate step for most people, whether through an external tool like this one, DAX Studio, or Tabular Editor. If you already work in Tabular Editor, its built-in formatter calls out to a web service — this page does the same job without the network round trip.