Free SQL Courses
SQL is the one skill on this site that shows up in almost every other track: data science, backend development, analytics, all of it eventually touches a database. Harvard CS50's Introduction to Databases with SQL is the most rigorous free option, covering both querying and database design. Khan Academy and Kaggle Learn both offer shorter, more practical introductions if you just need to write queries for a project. freeCodeCamp's Relational Database course pairs SQL with PostgreSQL in a Linux environment, which is closer to how it's actually used on the job. Google's Data Analytics certificate teaches SQL as one piece of a bigger analyst toolkit, worth considering if querying isn't your end goal on its own.
Related Learning Paths
Build projects in SQL
Editorial Guide
Best Free SQL Courses in 2026 (Ranked Honestly) →4 free SQL courses include a certificate
See all free coding courses with certificates →Khan Academy's interactive SQL course. Learn to create tables, insert data, query with SELECT, filter with WHERE, join tables, and aggregate with GROUP BY.
Learn SQL, PostgreSQL, and relational database concepts by completing projects in a Linux environment. Covers table design, joins, constraints, and database management. Free verified certificate.
Harvard's dedicated SQL course. Learn to design databases, write complex queries, use indexes, and work with SQLite, MySQL, and PostgreSQL.
Google's data analytics certificate. Covers data cleaning, analysis, visualisation with Tableau, SQL queries, and R programming. Free to audit; certificate costs money.
Intro to SQL (Kaggle Learn)
Kaggle Learn's 3-hour SQL micro-course using BigQuery. Covers SELECT, WHERE, GROUP BY, ORDER BY, JOINs, and writing efficient queries over large datasets. Notebook-based and free.