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UuByte
Free to start · No signup · 6 Languages

Learn programming.Interactive tutorials for every language.

Interactive tutorials in Go, Python, JavaScript, Java, Rust, and C++. Write real code in your browser, get instant feedback, and ace technical interviews.

  • ✓Write real code in your browser — zero setup
  • ✓Instant pass/fail feedback on every step
  • ✓Same concepts taught across all 6 languages
  • ✓Built-in LeetCode-style interview practice
Start freeInterview practicePractice exams

Join learners building real skills — no credit card required.

6

Languages

96

Lessons (Go)

11+

Problems

Free

to start

✓Step passed! +10 XP
🔥3-day streak
hello.go
Step 1 / 5Getting Started

Use fmt.Println() to print "Hello, World!" to the console.

1package main
2.
3import "fmt"
4.
5func main() {
6 fmt.Println("Hello, World!")
7}

Output

Hello, World!✓Correct!
See how it works

How it works

Four steps. Zero setup. Real code.

01
📖

Read

Short, focused lessons with clear explanations and real examples.

02
✏️

Code

Edit real code directly in your browser — no installs, no setup.

03
✓

Check

Instant feedback tells you if your output matches the expected result.

04
🏆

Level up

Earn XP, maintain streaks, and track your progress across all languages.

Pick your language

Same concepts, same structure — start in seconds with no setup.

🐹

Go

96 lessons

Master Go from the ground up: variables, concurrency, and APIs. Interactive lessons with runnable code and instant feedback. Start with free intro tutorials, unlock the full track with Pro.

Start learning→
🐍

Python

30 lessons

From basics to modules and async. Hands-on Python lessons with a built-in editor and instant runs. Free intro lessons; Pro unlocks the full curriculum.

Start learning→
⚙️

C++

32 lessons

C++ fundamentals, I/O, and modern patterns. Learn by doing with in-browser coding and feedback. Free starter tutorials; go further with Pro.

Start learning→
🟨

JavaScript

32 lessons

Core JS, the DOM, and Node-style modules. Bite-sized lessons with runnable examples. Try free lessons first; Pro opens the full path.

Start learning→
☕

Java

59 lessons

Java from syntax to interfaces and concurrency. Step-by-step tutorials with runnable code. Free intro; Pro for the complete track.

Start learning→
🦀

Rust

55 lessons

Ownership, borrowing, and fearless concurrency. Structured Rust lessons with in-browser coding. Free start; Pro for the full journey.

Start learning→
🎯

Ace your interview

LeetCode-style

Solve classic problems — Two Sum, LRU Cache, Merge Intervals and more — in any language. Same IDE, built right in.

  • Two Sumeasy
  • Three Summedium
  • Maximum Subarraymedium
  • Trapping Rain Waterhard
  • Valid Parentheseseasy
  • Climbing Stairseasy
  • + 5 more problems
Browse all problems
🐹

Go

11 problems

Arrays, hashmaps & goroutines

Start practicing→
🐍

Python

11 problems

Clean syntax, fast prototyping

Start practicing→
⚙️

C++

11 problems

Pointers, STL & performance

Start practicing→
🟨

JavaScript

11 problems

Closures, callbacks & async

Start practicing→
☕

Java

11 problems

OOP, generics & collections

Start practicing→
🦀

Rust

11 problems

Ownership, lifetimes & safety

Start practicing→
📋

Practice exams

Pro

Timed multiple-choice exams by language. Questions, duration, and pass threshold set per language. Pass to earn a certificate.

View practice exams
🐹

Go

40 per exam

45 min · 70% to pass · Certificate

Start exam→
🐍

Python

40 per exam

45 min · 70% to pass · Certificate

Start exam→
⚙️

C++

40 per exam

45 min · 70% to pass · Certificate

Start exam→
🟨

JavaScript

40 per exam

45 min · 70% to pass · Certificate

Start exam→
☕

Java

40 per exam

45 min · 70% to pass · Certificate

Start exam→
🦀

Rust

40 per exam

45 min · 70% to pass · Certificate

Start exam→