Readable queries, faster review
A query written on one line is fine for the machine and hard for a person. Formatting breaks the major clauses onto their own lines and indents the join and filter conditions beneath them, so the shape of the query — what it selects, from where, under which conditions — is legible at a glance. That is where most SQL bugs are caught.
A formatter, not a parser
This tool reflows and re-cases keywords rather than fully parsing the SQL, which is what lets it stay dialect-agnostic and instant. It will not tell you whether the query is valid or optimise it — it makes the query you already have easier to read, entirely on your device.