Best free LeetCode alternatives
Best free LeetCode alternatives to learn and practice SQL:
Beginner-Friendly
- SQLBolt (sqlbolt.com) — Lesson-based with gradual complexity; ideal for pure beginners who want a structured path before jumping into challenges.
- SQLZoo (sqlzoo.net) — Fully free, browser-based, with step-by-step interactive tutorials covering everything from basic
SELECTto window functions likeROW_NUMBERandDENSE_RANK; no installation needed. - W3Schools SQL (w3schools.com/sql) — Great quick reference and sandbox for experimenting with queries directly in the browser.
Intermediate / Interview Practice
- HackerRank SQL (hackerrank.com/domains/sql) — Fully free, hundreds of problems filterable by difficulty and topic, supports T-SQL / MS SQL Server dialect, and offers official skills certifications.
- DataLemur (datalemur.com) — Focused specifically on SQL interview questions from real companies like Meta, Amazon, and Google; free tier available.
- GUVI SQLKata — Completely free, beginner-to-intermediate level with structured SQL kata-style exercises.
Advanced / Real-World Data
- Mode Analytics SQL Tutorial (mode.com/sql-tutorial) — Uses real datasets and teaches analytical SQL with a polished online editor; excellent for data engineering work.
- StrataScratch (stratascratch.com) — Real interview questions from top tech companies; the free tier covers a solid number of problems.
Quick Platform Comparison
| Platform | Best For | Free? | SQL Dialect |
|---|---|---|---|
| SQLBolt | Absolute beginners | ✅ Fully free | Generic SQL |
| SQLZoo | Tutorials + exercises | ✅ Fully free | Multi-dialect incl. T-SQL |
| HackerRank | Interview prep + certification | ✅ Free tier | T-SQL, MySQL, Oracle |
| DataLemur | FAANG interview SQL | ✅ Free tier | PostgreSQL |
| Mode Analytics | Analytics & real data | ✅ Free | PostgreSQL |
| StrataScratch | Real company questions | Freemium | Python + SQL |