PromptHub
100% Free AI Coding Tools

Ship code faster with an AI pair programmer

Generate, explain, debug and optimize code in seconds — free, no account, powered by Google Gemini. From "write a scraper in Python" to "why is this query slow?", the Code Lab has you covered.

4

AI Coding Tools

15+

Languages

Free

No sign-up

SSR

100% server-rendered

The Code Lab

Four tools. Every stage of development.

From writing the first line to optimizing the last query — a full coding workflow in your browser.

Workflow

A complete dev loop, no install

1

Write

Describe what you need in plain English. The Code Generator returns clean, commented, production-ready code in your chosen language.

2

Understand & fix

Run any snippet through the Explainer, or paste a stack trace into the Debugger to get the root cause and the corrected code.

3

Optimize

Drop slow SQL into the Optimizer for formatted, rewritten queries with index suggestions — then ship it.

Sample output — SQL Optimizer

Before

SELECT orders.*, users.name FROM orders, users WHERE orders.user_id = users.id AND orders.status != 'cancelled' ORDER BY orders.created_at DESC

After

SELECT o.id, o.total, o.created_at, u.name
FROM orders o
INNER JOIN users u ON u.id = o.user_id
WHERE o.status <> 'cancelled'
  AND o.created_at >= NOW() - INTERVAL '90 days'
ORDER BY o.created_at DESC
LIMIT 100;

Who it's for

Every developer's second pair of eyes

Learning, building or debugging — the Code Lab works alongside you, in any language, without leaking your code to a public cloud IDE.

Python JavaScript PHP SQL TypeScript Java Go C#
  • Junior developers learning new languages
  • Engineers debugging errors before asking for help
  • Analysts writing and optimizing SQL queries
  • Students generating study examples in any language
  • Teams documenting legacy code with explanations
  • Freelancers shipping features faster

Your code stays private

Code is processed server-side and never stored, indexed or shared. Pages are 100% server-rendered — no client-side AI calls.

Privacy Policy

AI Code Lab — FAQ

Everything you need to know about the free AI coding tools.

Are the AI coding tools really free?

Yes. All four tools — Code Generator, Code Explainer, Debugger and SQL Optimizer — are free with no account or credit card. They run on the free Gemini API tier with automatic fallback.

Which programming languages are supported?

Python, JavaScript, TypeScript, PHP, Java, C#, Go, Rust, Ruby, SQL and 15+ more. Just type the language you want in the field.

Is my code stored anywhere?

No. Code is sent to the LLM to generate a response, then discarded. PromptHub does not store, index or share the code you paste.

How accurate is the generated code?

The models are strong at common patterns and boilerplate. Always review generated code for your specific context, run your tests and never blindly deploy AI code into production.

Can it help with errors from my stack trace?

Yes. The Debugger accepts your code plus an optional error message or stack trace and returns the root cause with a corrected version.

Why is the SQL Optimizer useful?

It formats messy queries, rewrites inefficient patterns (e.g. SELECT *, implicit joins, missing limits) and suggests indexes for MySQL, PostgreSQL, SQLite and SQL Server.