The Best Free App to Learn SQL on Your Phone
If you learned to love SQL on interactive sites like SQLBolt — real tables, a query box, instant right-or-wrong feedback — you already know the fastest way to learn SQL is by doing it, not watching videos. The catch: those tools live on the desktop web. When you’ve got five spare minutes on the bus, you want to practice on your phone.
That’s exactly what SQL Prep — Learn & Practice is: the learn-by-doing approach, on iOS, gamified, and free.
Why practice SQL by doing (not watching)
In the age of AI, SQL is still the #1 skill for anyone working with data — and it’s a skill you build with your hands, not your eyes. Reading about a JOIN is forgettable; writing one against a real table, getting it wrong, seeing why, and fixing it sticks. That’s the whole idea behind interactive SQL practice, and it’s why the format works so well.
Doing it on mobile just removes the last excuse: five focused minutes a day beats a two-hour session you never start.
What SQL Prep gives you
It turns queries into a game. You see a real database table with sample data, read a task, write your query, and get instant feedback:
- See a real table with sample rows
- Read the challenge — e.g. “Find all orders over $100”
- Write your SQL query
- Get instant feedback with a detailed explanation
- Earn XP, keep your streak, and track progress
Topics, from beginner to interview-ready:
- Start here —
SELECT,WHERE,ORDER BY - Level up —
GROUP BY,HAVING,COUNT - Get serious —
JOIN,LEFT JOIN,INNER JOIN - Go pro — subqueries & window functions
- Boss levels — real-world interview scenarios
There’s also an AI-powered SQL generator built in: describe what you need in plain English and it writes the query, so you can study the pattern instead of getting stuck. 40+ expert-crafted challenges, 5-minute daily sessions, and it’s free.
SQLBolt vs SQL Prep — which when?
They’re friends, not rivals:
| SQLBolt (web) | SQL Prep (iOS) | |
|---|---|---|
| Where | Desktop browser | iPhone / iPad, anywhere |
| Format | Interactive lessons | Gamified challenges + XP/streaks |
| Extras | — | AI SQL generator, interview levels |
| Price | Free | Free |
Use SQLBolt at your desk for a first pass; use SQL Prep to keep the streak alive and drill on your phone between other things. The mobile habit is what turns “I did a tutorial once” into “I actually know SQL.”
The bottom line
If you want to actually learn SQL — not just read about it — do it interactively, and do it daily. On the desktop, SQLBolt is a great start. On your phone, SQL Prep — Learn & Practice makes it a free, five-minute habit with instant feedback and an AI helper when you’re stuck.