SQL Formatter tidies a SQL statement for reading: it upper-cases keywords and starts each major clause, JOIN, and AND or OR on a new line.
It works by tokenising, not full parsing, so it will not catch syntax errors. It runs in your browser.
It knows a broad set of standard keywords. Dialect-specific syntax is passed through untouched, which is usually fine for formatting.
No. It only changes whitespace and keyword case. A broken query stays broken.
Yes, there is an option to leave the case as you typed it.
No. The tool runs entirely on this page.