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PyCodeIt

Free interactive learning platform for Python code tracing, SQL queries, and technical interviews. Built for bootcamp grads, computer science students, and engineers.

Python Practice

  • Learning Center
  • For loop tracing
  • List tracing
  • Dictionary tracing
  • Decorators practice
  • Python Tracing Guide
  • Python Output Questions

SQL Practice

  • SQL Fundamentals
  • Relational JOINs
  • Window Functions
  • CTEs & Set Operators
  • SQL JOINs Guide
  • Window Functions Guide

Legal

  • About
  • Contact
  • Privacy Policy
  • Terms of Service

© 2026 PyCodeIt. Sandbox keys are processed strictly client-side.

#1 Python Dry Run & Trace Table Sandbox

Predict output. Query databases.
Pass technical interviews.

Master Python dry-runs and trace tables line by line, or write and verify SQL queries against live in-browser databases. Built specifically for technical phone screens and coding assessments.

Python Sandbox

Syntax Tracing & Logic

Analyze and dry-run decorators, mutable defaults, variable scopes, closures, and loops to predict console stdout.

100+ challenges

SQL Playground

WASM SQLite Engine

Write queries and check executions against HR, E-Commerce, and Competition database tables in real-time.

200+ queries

Interactive Curriculum

Practice Python tracing and SQL queries in one place.

View Interview Guide →

In-Browser Sandbox

Run Python trace problems and SQL queries without installing anything. The Python track uses a frame-by-frame simulator; the SQL track uses a WebAssembly SQLite engine with real HR, e-commerce, and competition table data.

AI-Powered Evaluation

Connect your own Gemini, Groq, or OpenRouter API key and get graded feedback on both Python submissions and SQL queries. Every evaluation includes a step-by-step explanation of the correct answer.

Structured Learning Paths

Follow topic-by-topic tracks for Python from basics through decorators, and SQL from SELECT fundamentals through window functions and CTEs. Earn XP, build streaks, and track your progress on the leaderboard.

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Platform Breakdown

Python Code Tracing

Dry-running is the practice of mentally executing code line by line to predict output without a runtime. It reveals variable scope rules, mutable aliasing, and exception propagation in a way that reading alone does not.

SQL Live Playground

Write real queries against HR employee tables, e-commerce order data, and competition leaderboard schemas. Results appear instantly using an in-browser SQLite engine with no backend calls.

Interview Guide

Access our comprehensive guide on mastering technical interviews. Learn the three-phase methodology: Prediction, Completion, and Creation.

Read Guide →

Private by Design

Your API keys are stored only in your browser's local storage and are never sent to PyCodeIt servers. All LLM calls go directly from your browser to the provider.

Python Practice Tracks cover 100+ structured topics from variables and loops through decorators and OOP.
SQL Practice Tracks cover 200+ queries from basic SELECT through window functions and CTEs.
Looking for policies? Read our Privacy Policy and Terms of Service.
FAQ

Frequently Asked Questions

Everything you need to know about practicing on PyCodeIt.

Is PyCodeIt completely free?
Yes it is 100% free. You can practice Python tracing, SQL queries, and access hundreds of interview challenges without any account. Creating a free account unlocks XP tracking, daily streaks, and the leaderboard.
Do I need to install Python or any software?
No installation needed. Everything runs in your browser. The SQL engine uses WebAssembly (WASM SQLite) and Python challenges are evaluated server-side. Just open the website and start practicing immediately.
What Python topics are covered?
100+ topics: variables, loops, lists, dictionaries, functions, decorators, closures, OOP, mutable defaults, scoping, recursion, and advanced patterns, all structured the way real interviews test them.
What SQL topics are covered?
200+ exercises from basic SELECT statements through GROUP BY, JOINs, subqueries, window functions (ROW_NUMBER, RANK, LAG, LEAD), recursive CTEs, and scenario-based playbooks modelled after real company data.
How does this help me pass technical interviews?
PyCodeIt mirrors real interview formats. Python challenges train output prediction, the same mental model interviewers evaluate. SQL playbooks use real-world schemas (e-commerce, rideshare, hospital) identical to FAANG-style data engineering rounds.
Are my API keys private and secure?
Completely. Your AI provider keys (OpenAI, Groq, OpenRouter) are stored only in your browser's local storage and are never sent to PyCodeIt servers. All AI calls go directly from your browser to the provider.
Can I share or embed my coding stats?
Yes! PyCodeIt provides an embeddable profile widget. Copy the iframe code from your dashboard and paste it onto any portfolio, blog, or GitHub README. It automatically fetches your live XP, streak, accuracy, and level.