BYTE by Reaves

Every level is a real CS2023 knowledge area with a stated thinking level. Clear one, earn XP, keep the streak going.

36 levels. Three a day.

Free · offline · no account

36Levels

6Zones

3Per day

0Ads

Start level 1 See a level

The path0 / 36

The Basics

Power Tools

The Browser

Real World

Your Empire

AI & Advanced

What it looks like

Real screens from the app — not mockups.

Every level, by name

The whole path, visible before you start. Nothing is locked.

36 levels · 6 areas

Stuck? Ask BYTE.

It answers from the levels themselves — and says no when the answer is not in them.

Grounded, not generated

Every reply is drawn from a lesson you can open. There is no model call, and nothing you type leaves the device.

36 of 36 levels contribute an answer

It refuses what it does not know

A tutor that invents is worse than one that says no.

off-topic questions are declined, not guessed

Grounded in the standard

Not a topic list — a curriculum.

ACM/IEEE-CS CS2023

Every level carries a real knowledge-area code from the profession's own curriculum standard.

11 knowledge areas covered

Bloom's revised taxonomy

Each level states the kind of thinking it asks for, so the path climbs instead of repeating.

5 Understand · 21 Apply · 5 Analyze · 3 Evaluate · 2 Create

What happens in a level

Every level runs the same three steps. Here is level 1, start to finish.

1 · Concept — read it in plain language

An analogy first, then the idea. Level 1 opens with the recipe analogy — you write step-by-step instructions, the computer is the chef, it follows them exactly, in order, with no improvising. No syntax until the idea lands.

objective: what a program IS before writing one — the mental model, not a keyword

2 · Code Editor — run it yourself

Working code arrives with one thing left to change. Press Run and the output appears underneath. Nothing to install, no account, no server.

Run, Reset and Hint, in the page

3 · Quiz — prove you got it

A short check on what the level asked you to do. Miss one and it names the idea to re-read, not just the wrong answer.

36 levels, each ending in a check that earns XP

Strings & Text

A string is a sequence of characters. Template literals — backtick strings — let you embed a value with ${...} instead of gluing pieces with +, which is easier to read and much harder to get wrong.

const name = "Ada";
console.log(name.length);              // 3
console.log(name.toUpperCase());       // "ADA"
console.log(`Hello, ${name}!`);        // "Hello, Ada!"

The 11 knowledge areas, and how many levels each

ACM/IEEE-CS CS2023. Codes taken from csed.acm.org — the profession's own map, not ours.

SDF — Software Development Fundamentals

Strings & Text · What IS Code? · Variables · Data Types

11 levels

SE — Software Engineering

Debugging Tools · Testing Basics · Reading Documentation · Error Handling

8 levels

HCI — Human-Computer Interaction

Forms & Input · Layout — Flexbox & Grid · HTML & DOM · CSS Basics

5 levels

FPL — Foundations of Programming Languages

Scope & Closures · Array Methods

2 levels

DM — Data Management

JSON & Data Shapes · Storage & State

2 levels

AI — Artificial Intelligence

Commanding Claude Code · Agent Architecture

2 levels

SEP — Society, Ethics, and the Profession

Economics of AI Dev · Your Playbook

2 levels

SPD — Specialized Platform Development

DOM Manipulation

1 level

PDC — Parallel and Distributed Computing

Async & Promises

1 level

NC — Networking and Communication

APIs & fetch()

1 level

SF — Systems Fundamentals

The Full Stack

1 level

Works on a plane

No connection required, ever. Nothing you write leaves your device.

Network required

None

Account required

None

Data collected

None

Ads

None

Built to be trusted

Every hint is written and reviewed. When BYTE does not know something, it says so.

Free · offline · no account

Built for ages 13 and up.