Ruby Online Compiler: Run Ruby 4.0 in Your Browser

What runs your code

Version	Ruby 4.0
Compiled with	No separate step: the run command compiles or interprets it
Run with	`ruby code.rb`
Limits	30 seconds, 512 MB of memory, 2 CPUs, 64 KB of output per stream, no network
Typical run	0.69 s, and 0.86 s for the slowest 1 in 20 (how we measured)

Good to know

Programs run on Ruby 4.0 with its standard library.
gets reads the next line of the Input tab; gets.chomp drops the newline.
Only the gems that ship with Ruby are available.

Run Ruby from your own code

Send the code and its input to the sync endpoint with an API key, and the output comes back in the response. The API docs cover the async endpoint with callbacks and every response field.

Terminal

curl -X POST https://api.onlinecompiler.io/api/run-code-sync/ \
  -H "Authorization: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "compiler": "ruby-4.0",
    "code": "name = gets.chomp\nputs \"Hello, #{name}!\"",
    "input": "Ada"
  }'

The response has output ("Hello, Ada!\n" here), error, exit_code, time and memory.

Put a runnable Ruby example on your site

The editor above is the embeddable widget. Add the script and a div with your widget key, and your readers can edit and run the code without an account:

example.html

<script src="https://onlinecompiler.io/widget.js"></script>

<div class="runcode" data-key="YOUR_WIDGET_KEY" data-lang="ruby-4.0">
  <script type="text/plain">
    name = gets.chomp
    puts "Hello, #{name}!"
  </script>
</div>

On a platform that takes an iframe but not a script, such as many course sites, use the iframe embed. For Docusaurus, MkDocs, Sphinx and Mintlify, see runnable code examples in docs.

Other languages

Python, C, C++, Java, C#, F#, Go, Rust, PHP, Haskell, TypeScript.

Frequently asked questions

Is this Ruby online compiler free?

Yes. Running Ruby on this page needs no account and shows no ads. To run Ruby from your own app or site, the API and the widget are free up to 100,000 runs a month, commercial use included.

Can my Ruby program read input?

Yes. Type it in the Input tab before you run, and the program reads it from standard input. The whole input is sent when you press Run, so a program can't ask for more while it runs.

Can I use Ruby libraries?

Ruby's standard library and the gems bundled with it. Other gems can't be installed, as programs have no network access.

How long can a program run?

Up to 30 seconds, with 512 MB of memory and 2 CPUs. A program still running at 30 seconds is stopped with exit code 124, and output over 64 KB per stream is cut.

Where does my code run?

On our servers, in a fresh gVisor sandbox with no network access that is deleted when the run ends. Each run is kept in execution history with its output; the security page says what is stored.