DB Fiddle provides free online SQL playground for testing queries, creating demos, and sharing code without local database setup. Completely free with no account required for basic usage. Supports MySQL 5.5-8.0, PostgreSQL 9.4-15, and SQLite 3.27-3.39. Users create schema (DDL) in left panel, write queries in right panel, and execute against temporary database instances. Shareable URLs enable saving and sharing fiddles for collaboration, Stack Overflow answers, or documentation. Each fiddle gets unique URL preserving schema and queries. No AI features—simple execution environment. Limitations include no persistent storage, timeout on long-running queries, and no advanced database features (extensions, custom functions). Best suited for quick testing, demonstrating SQL concepts, and sharing reproducible examples. Alternatives include SQL Fiddle (original, less maintained) and db-fiddle.com. Page should cover: supported database versions, schema/query workflow, sharing capabilities, limitations, comparison with local development, and use cases for teaching and documentation.