About Fulfledge

What we are aiming at

The wall you hit when you start programming is usually not the syntax. It is getting a development environment ready, and finding a solid block of time at a desk. We have watched a lot of people lose their "I want to try this" while waiting for those two things to line up.

Fulfledge asks for neither of them. Nothing to install and nothing to set up — open the browser on your phone and you can write code and run it right away. Ten minutes on the train, five minutes before bed: those scraps of time become your study time.

How you learn

A lesson does not stop at reading. You take in one idea from a few short slides, then write the code yourself straight away. What you write runs on the spot, and if you got it wrong, the error shows up as it is.

• Input — A few slides, and just one idea in them
• Output 1 — Basic exercises where you trace the syntax
• Output 2 — Practice exercises where you work it out yourself

We show error messages exactly as the browser produced them, without rewording them. Those are the messages you will meet in real development, so we would rather you got used to reading them early.

What you can learn right now

Right now there are 10 courses, 476 lessons and 5987 exercises.

• JavaScript — Build the way of thinking that programming runs on
• Python — Learn how programming thinks, with fewer symbols in the way
• TypeScript — Add types to JavaScript and catch mistakes before you run anything
• HTML & CSS — Build what a web page looks like
• Build a to-do app — Bring HTML, CSS and JavaScript together into your first working app
• SQL — Get data in and out of a database
• How computers work — Check what is happening underneath your code, using past exam questions
• How web apps work — Read what actually travels between the browser and the server
• The command line — Type into a real Linux running inside your browser and learn where files live
• Git — Commit your changes so you can always go back. Create branches, share them on remote repositories, and get reviewed through pull requests.

There is also a Playground, where nothing gets marked. It is the place to try out the syntax you picked up in a lesson, or to cause an error on purpose and get used to reading it.

Your learning path

The goal is for you to be able to build, with your own hands, a portfolio you can show when you apply for jobs. Here is the order we are laying that path out in.

• Pick up the way programming thinks, with JavaScript or Python
• Learn to write with types, in TypeScript (Optional challenge)
• Learn how to build the look of a page, with HTML and CSS
• Build a to-do app on your own computer
• Learn how to handle data, with SQL
• Back up your IT fundamentals with past questions from Japan's IT fundamentals exam (Optional challenge)
• Put a database into the to-do app, and get to know server and client
• Learn to handle files and permissions on Linux, from the command line
• Learn to record changes and work with others, with Git
• Use a framework to finish your portfolio

The units marked "Optional challenge" are not required. Skip ahead, or come back to them later — either is fine. TypeScript is one you will want to have been through before you reach frameworks, because the JavaScript people write at work is effectively TypeScript now.

The first half stays inside the app. The second half moves over to building things on your own computer. Fulfledge is the way in, not the place you stop.

What matters to us

• More time writing than reading — Rather than add more explanation, we add more chances to move your hands.
• One idea per lesson — We cut things small enough that you can tell for yourself whether you got it.
• Mistakes are material too — We show errors and wrong answers instead of hiding them, and use hints to get you to where you can solve it yourself.
• The phone comes first — Every screen and every action is designed around a phone held upright.
• Everything here is written from scratch — Neither the text nor the code examples are copied from anyone else's material.

How the material is made

To keep the material accurate, it is written and published like this.

• The material is written from scratch in Japanese, and the English version is a translation of it. Neither copies text or code from anyone else's material.
• Learning sites and books we referred to are used only as a yardstick for what order to cover things in and how much to cover at once.
• Before anything is published, the model answer to every exercise is actually run, and a machine checks that it produces the expected result. JavaScript, Python, TypeScript and SQL are run and their output compared; command-line answers are typed one by one into a real Linux.
• The questions in the computer-fundamentals course are past questions from Japan's Fundamental Information Technology Engineer Examination, published by IPA (the Information-technology Promotion Agency), used with their sources cited. Every explanation is written from scratch.
• If you spot a mistake in the material, please let us know through the contact page. We will check it and fix it.

Update history

2026-09-20

Published the guides (learning on just a phone, how to learn JavaScript, what each course teaches)

2026-09-19

Added two JavaScript chapters (the data toolbox, waiting for slow work), three TypeScript chapters on types used in real work, and two to-do app chapters on input validation and event delegation

2026-09-16

Added the Git course and the to-do app course

2026-09-14

Finished the Python course through chapter 12. The editor now flags full-width symbols

2026-09-09

Added review, which brings back questions you solved after a day or so

2026-09-08

Moved to our own domain, fulfledge.app. A single slide or question can now be shared by URL

2026-09-07

Published the English version

2026-08-24

Renamed the service to Fulfledge

2026-08-23

Added the How web apps work course

2026-08-21

Added three courses: TypeScript, computer fundamentals, and the command line

2026-08-20

Added the Python course

2026-08-19

Launched with three courses (JavaScript, HTML & CSS, SQL) and the playground

Who runs this

Site owner

Fulfledge

Contact

fulfledge.app@gmail.com

Online since

2026

For thoughts or bug reports, use the contact page. How personal information is handled is written up in the privacy policy.