Online Ruby Compiler

Write, run, and debug Ruby code online in a full-featured browser IDE. Work with multiple files and gems, save your workspace, and collaborate in real time.

Version

Pre-installed Libs

🚀 233,813 total executions (97 this month)

Output

Practice Python with coding challenges

Solve hands-on problems right in this editor: run the sample tests, submit, and get an AI code review.

All Python challenges

Easy

Rectangle Perimeter

Compute the perimeter of a rectangle from its sides.

You'll learn ArithmeticReturn values

BeginnerLearning-pathVariables

View solutions (6)

Easy

Days in a Month

Return how many days a month has, including leap years.

You'll learn Calendar rulesHelper functions

BeginnerConditionsFunctionsLearning-path

View solutions (3)

Easy

Dot Product of Two Vectors

Multiply two vectors element by element and add the results: the core operation of every neuron.

You'll learn VectorsDot product

Neural networksaimachine learning

View solutions (3)

Easy

Distance Between Points

Compute the straight-line distance between two points.

You'll learn Pythagorean theoremSquare roots

BeginnerFunctionsLearning-pathmath

View solutions (2)

Easy

Average of Three

Average three whole numbers.

You'll learn ArithmeticDivision

BeginnerLearning-pathVariables

View solutions (2)

Easy

To-Do List

Keep a list of tasks: add them, mark them done, remove them and report what is still pending.

You'll learn Typed collectionsRecords

BeginnerSimulationStrings

View solutions (1)

Easy

Prime Number Check

Decide whether a number is prime.

You'll learn DivisibilityLoop optimization

BeginnerLoopsNumbersStudent-beginner

View solutions (1)

Hard

Word Break

Decide whether text can be split into dictionary words.

You'll learn Prefix DPString segmentation

AdvancedDynamic-programmingHackathonStrings

View solutions (1)

Easy

Count Pairs With a Sum

Count pairs of positions whose values add up to a target.

You'll learn Pairs of indexesAvoiding double counts

ArraysBeginnerLearning-pathNested-loops

View solutions (1)

Easy

Missing Number

Find the one number missing from 0..n.

You'll learn Arithmetic seriesSum difference trick

ArraysBeginnerStudent-beginnermath

View solutions (1)

Medium

K-th Smallest Element

Find the k-th smallest value without fully sorting.

You'll learn QuickselectPartitioning

AdvancedCompetitive-programmingSorting

View solutions (1)

Easy

Min and Max Together

Find the smallest and largest value in one pass.

You'll learn Single passMultiple return values

ArraysBeginnerFunctionsLearning-path

View solutions (1)

💎 About This Ruby Online Executor

The CodeUtility Ruby Executor allows you to write, run, and test Ruby code instantly in your browser - no installation or setup needed. It runs in secure, isolated environments powered by real Ruby interpreters, supporting versions 2.7, 3.1, and 3.2.

Whether you're practicing Ruby fundamentals, testing algorithms, or learning object-oriented programming, this tool provides a simple and interactive console for immediate feedback.

You can use it to explore Ruby syntax, play with gems, or debug short snippets without configuring a local environment. It’s ideal for learners, backend developers, and anyone experimenting with Ruby-based logic.

All executions are processed in sandboxed environments to ensure safety and reliability while preserving real Ruby behavior.

More than a code runner

Use a multi-file editor, an isolated execution terminal, runtime-specific libraries, persistent workspaces, sharing, and real-time collaboration from the same executor.

How to use this executor?

Choose a runtime, open or create a file, write your code, and select Run. Output appears in the terminal, while signed-in users can keep files in a workspace, install libraries, and collaborate through shares.

Select a version and edit the current file or open another workspace file.
Run the code, provide input in the terminal when requested, and review saved run history.
Use libraries, workspace tools, sharing, and chat when your task needs more than one snippet.

Start coding

VersionSelect a runtime before running. Installed libraries belong to the selected language version.
Open files lists unopened text files. Select one to open it in an available editor tab.
Run executes the active file with its workspace available to the program.
Stop ends the current execution before its time limit.
Advanced Mode opens the IDE layout with a file explorer and movable, resizable terminal.

Workspace and libraries

New file creates a file in the selected parent directory and opens it in the editor.
New folder creates a directory, up to the supported nesting depth.
Upload files adds one or more safe files to a directory.
Download saves a file or a zipped directory to your device.
Copy duplicates a workspace file or directory.
Rename changes a file name and updates its open tab and history.
Move relocates an item; files and directories can also be dragged.
Delete removes an item after confirmation and closes its open editor tab.
Pre-installed Libs shows packages already included in this runtime.
Add Lib installs a private package for your account and selected runtime.

Terminal and assistance

Run history opens previous and next saved outputs.
Run with switches Ruby between the execution server and Browser Ruby. Browser Ruby synchronizes workspace files, while account-installed libraries and interactive terminal input require the execution server.
Copy output copies the current terminal text.
Clear output removes all saved run outputs after confirmation.
Explain summarizes the active code.
Recents opens recent explanations and results.
Settings changes fonts, themes, and visible toolbar buttons.

Sharing and collaboration

Share publishes the current file, a directory, or the whole workspace as a snapshot or live workspace. You control link access and who may save changes.
Logs records saved collaborator actions in a shared workspace.
Share chat lets signed-in participants message, mention people, share code blocks, and see online or typing members.
Live collaboration shows collaborator cursors and saved file updates. View-only users can load the latest version or keep temporary edits.

Quotas and limits

Execution time is limited to 20 seconds per server run. Use Stop when you want to end it sooner.
Workspace storage allows 100 files, 100 directories, and 10 MiB total for each signed-in user workspace and language.
Files and folders are limited to 1 MiB per file and 5 nested directory levels. Files generated by your code follow the same quota.
Private libraries are limited to 10 installed packages for each account and runtime.
Share snapshots can contain up to 100 files, 1 MiB per file, and 2 MiB total.
Share invitations support up to 25 people per share, with access and saving permissions managed separately.
Share chat allows 2,000 characters per message and 10,000 messages per share.
Quota enforcement also applies while code is running. A write that exceeds file count, size, storage, or nesting limits is rejected safely.

Good to know Only run code and install packages you trust. Execution is isolated and limited, but your program can still modify files inside a writable workspace up to its enforced quota.

💡 Ruby Basics Guide for Beginners

1. Declaring Variables and Constants

Ruby is dynamically typed. Constants start with uppercase letters and are not meant to change.

x = 10
pi = 3.14
name = "Alice"
is_active = true

MAX_USERS = 100
APP_NAME = "CodeUtility"

2. Conditionals (if / case)

Use if, elsif, else, or case for control flow.

x = 2
if x == 1
  puts "One"
elsif x == 2
  puts "Two"
else
  puts "Other"
end

case x
when 1
  puts "One"
when 2
  puts "Two"
else
  puts "Other"
end

3. Loops

Use while, until, or iterators like each.

i = 0
while i < 3
  puts i
  i += 1
end

[1, 2, 3].each do |n|
  puts n
end

4. Arrays

Arrays store ordered lists of elements. Access using indexes.

fruits = ["apple", "banana", "cherry"]
puts fruits[0]
puts fruits.length

5. Array Manipulation

Use push, pop, slice, and reverse for working with arrays.

fruits.push("kiwi")
fruits.pop
puts fruits[1..2]
puts fruits.reverse

# Array comprehension
squares = (1..5).map { |x| x * x }
puts squares

6. Console Input/Output

Use gets.chomp to read input and puts/print for output.

print "Enter your name: "
name = gets.chomp
puts "Hello, #{name}"

7. Functions

Define functions using def. You can pass arguments and return values.

def greet(name)
  "Hello, #{name}"
end

puts greet("Alice")

8. Hashes

Hashes are key-value pairs, like dictionaries or maps.

person = { "name" => "Bob", "age" => 25 }
puts person["name"]

# Symbol keys
person = { name: "Alice", age: 30 }
puts person[:name]

9. Exception Handling

Use begin-rescue-end to catch exceptions and handle errors gracefully.

begin
  raise "Something went wrong"
rescue => e
  puts e.message
end

10. File I/O

Read and write files using File methods or IO classes.

File.write("file.txt", "Hello File")
content = File.read("file.txt")
puts content

11. String Manipulation

Ruby strings support many methods: length, gsub, split, etc.

text = " Hello World "
puts text.strip
puts text.upcase
puts text.gsub("Hello", "Hi")
puts text.split

12. Classes & Objects

Ruby is fully object-oriented. Use initialize to define constructors.

class Person
  def initialize(name)
    @name = name
  end

  def greet
    "Hi, I'm #{@name}"
  end
end

p = Person.new("Alice")
puts p.greet

13. References (Object Mutation)

All variables hold references to objects. Modifying an object inside a function affects the original.

def modify(arr)
  arr << "changed"
end

data = ["original"]
modify(data)
puts data.inspect  # ["original", "changed"]