The implementation uses sql-formatter 15.8.2 and passes one explicitly selected dialect object to its tokenizer and layout engine. It does not guess a dialect from the input.
Seven modes are exposed: Standard SQL, PostgreSQL, MySQL, SQLite, SQL Server Transact-SQL, Oracle PL/SQL, and BigQuery. Dialect selection controls recognized identifiers, parameters, operators, functions, and keywords.
The formatter changes whitespace and can preserve, uppercase, or lowercase recognized keywords and data types. Function and identifier casing remain preserved; quoted strings, quoted identifiers, comments, placeholders, and statement semicolons remain source tokens.
A formatter parse is narrower than database validation. It may reject an unsupported token with a safe line and column, yet it can also lay out an incomplete or semantically invalid statement. It never connects to a schema, executes a query, or returns an execution plan.
Input is bounded before parsing to 1,000,000 UTF-8 bytes, 20,000 lines, and 100,000 UTF-8 bytes per line. NUL text, leading custom DELIMITER directives, and leading stored routine or trigger definitions fail closed.
Processing, copying, and SQL file creation stay in the browser. Telemetry is limited to coarse operation metadata and stable errors; query text and formatted output are not added to analytics events.