HowToCodePage

Learn to code, one page at a time

649 free lessons across 111 courses — HTML, CSS, JavaScript, Python, SQL, Git, Linux, Docker and more. Original, ad-light tutorials with runnable examples you can copy and edit on the page, plus 37 developer tools that never upload your data.

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How this site is organised

Tracks, then courses, then lessons — so you always know what to read next.

Open the full catalogue — 111 courses across 12 tracks.

Course catalogue

Grouped the way developers actually learn: by track.

🐍

Python & Data Science

Python itself, plus the web and scientific-computing ecosystem around it.

13 courses
🤖

AI & Intelligent Development

Large language models, agent engineering, machine learning and computer vision.

17 courses
🎨

Front-end Development

Markup, styling, client-side programming, frameworks and visualisation.

19 courses
⚙️

Back-end Development

Server-side languages, frameworks and the protocol they speak.

10 courses
🗄️

Databases

Relational and NoSQL storage: modelling, querying, indexing.

6 courses
📱

Mobile Development

Native and cross-platform apps for phones and tablets.

6 courses
🚀

DevOps & Tooling

Version control, containers, pipelines and operations.

8 courses
💻

Programming Languages

General-purpose languages: syntax, type systems and idioms.

7 courses
🧠

Computer Science Fundamentals

Algorithms, data structures, networks, systems — plus everyday developer references.

9 courses
🧾

XML & Web Services

Structured data description and inter-system interfaces.

6 courses
🟣

.NET

The Microsoft stack: web, desktop and data access.

5 courses
🌐

Building a Website

From a domain name to a live, fast, indexable site.

5 courses

See all 111 courses →

Start with a longer course

The most detailed courses on the site right now.

Python 3

The current Python: syntax, collections, functions and files.

14 lessons

HTML

The structure and meaning of a web page.

14 lessons

CSS

Styling, layout and the cascade.

14 lessons

JavaScript

The programming language of the web.

14 lessons

SQL

Querying, writing and speeding up relational data.

14 lessons

MySQL

The most widely deployed open-source database.

14 lessons

Browser-only tools

No upload, no account. Everything runs locally in your tab.

🔡

Base64 encoder / decoder

Convert text to and from Base64. Runs entirely in your browser — nothing is uploaded.

🔒

Hash & checksum

Compute MD5, SHA-1, SHA-256, SHA-384, SHA-512 of text using your browser. No upload.

🧱

JSON formatter & validator

Pretty-print, minify, and validate JSON. Runs locally in your browser.

🔗

URL encoder / decoder

Percent-encode and decode query strings and path segments. Browser-only.

See all 37 tools →

Common questions

Is HowToCodePage free?
Yes. Every tutorial and every tool is free to read and use, with no account, no paywall and no email sign-up. The site is supported by advertising.
Do I need to install anything to follow the tutorials?
No. Lessons are read in the browser, and the 37 developer tools all run on your own device — nothing you paste into them is uploaded anywhere.
Which language should a beginner start with?
Start with HTML and CSS so you get something visible on screen quickly, then JavaScript to make it interactive. If you are coming from another language or want something for data work, start with Python instead.
How long does a course take?
Lessons are short and focused on one topic each, so most take about ten to fifteen minutes. A course of twelve lessons is a weekend of casual reading, or an afternoon if you type out every example.
Are these lessons official documentation?
No. They are original, synthesised teaching material written to explain how something works and what usually goes wrong. Always check the official documentation for the current API surface.

Content refreshed 2026-09-18.