RegSQL vs SQLFluff

RegSQL is a web SQL workspace combining browser-local formatting with optional AI assistance. Formatting runs in a browser worker without an account or server round trip. It adjusts whitespace and casing while preserving query logic, aliases, and comments, and accepts multi-statement input up to 1 MB. Listed dialects are PostgreSQL, MySQL, MariaDB, SQLite, BigQuery, SQL Server, Snowflake, and Oracle PL/SQL. AI tools can generate SQL from a description, explain an existing query, or suggest a repair. Formatting may reveal parsing problems, but RegSQL does not connect to a database or verify tables, columns, permissions, data types, or runtime behavior. SQL, prompts, and schema text are sent to the AI provider only after Generate, Explain, or Repair is chosen. The Free plan is free, billed Forever, with unlimited local formatting and 20 AI requests monthly. Indie costs $8 a month or $72 billed yearly ($6/month).

SQLFluff is an open-source, dialect-flexible SQL linter designed for ELT applications. It reports style and syntax issues, parses SQL without database access and can automatically fix many violations with one command. Documentation describes support for more than 25 dialects, including T-SQL, PostgreSQL, BigQuery and Snowflake, alongside more than 70 rules for style, structure and best practices. Jinja templating and dbt are supported, and CI/CD integration includes GitHub Actions output for pull-request annotations. SQLFluff is free under the MIT License and installs from PyPI with pip or another Python package manager. It does not execute SQL itself, but templating macros such as dbt's run_query may execute arbitrary SQL. The Jinja templater uses Jinja2 SandboxedEnvironment to limit unsafe code execution. The dbt templater requires the relevant adapter and sqlfluff-templater-dbt package; models accessing a database during compilation require database access. Community support includes documentation, GitHub, Slack and Stack Overflow.