sqlcrab.com

mx

ns

dns3.p09.nsone.net

dns4.p09.nsone.net

dns2.p09.nsone.net

dns1.p09.nsone.net

caa

txt

dmarc

User-agent: *
Allow: /
Disallow: /dashboard
Disallow: /login

# AI crawlers
User-agent: GPTBot
Allow: /

User-agent: OAI-SearchBot
Allow: /

User-agent: ChatGPT-User
Allow: /

User-agent: ClaudeBot
Allow: /

User-agent: PerplexityBot
Allow: /

User-agent: Google-Extended
Allow: /

Sitemap: https://sqlcrab.com/sitemap.xml

# SQLCrab

> Ace the SQL interview with real Postgres labs. SQLCrab is a browser-based SQL interview practice app: graded labs, a free tutorial, concept cards, and a sandbox — all running on a real Postgres engine (PGlite) with no servers or install.

SQLCrab helps people prepare for data/SQL interviews (online screens, take-homes, live coding). Free content works without signup; a license unlocks Pro labs.

## Product

- [Home](https://sqlcrab.com/): Overview, live hero demo, and FAQ
- [Practice labs](https://sqlcrab.com/practice): Graded SQL interview questions by difficulty, topic, and company
- [SQL tutorial](https://sqlcrab.com/learn): Free lessons from SELECT basics to recursive CTEs
- [Concept cards](https://sqlcrab.com/concepts): SQL reasoning, stats/ML, and behavioral + AI interview cards
- [SQL sandbox](https://sqlcrab.com/sandbox): Free playground with seven realistic datasets
- [Sign in](https://sqlcrab.com/login): Verify a license key to unlock Pro labs

## Key facts

- Engine: real Postgres via PGlite, running entirely in the browser (Web Worker)
- Grading: column-by-column result comparison, not string matching
- Content: original interview-style questions and lessons (not scraped)
- Pricing: free tutorial/sandbox/preview labs; paid license for full lab set
- Language: English

## Optional

- [robots.txt](https://sqlcrab.com/robots.txt)
- [sitemap.xml](https://sqlcrab.com/sitemap.xml)