Open .RB files online

Q: How do I open a .rb file online?

Drag the `.rb` onto the page (or click to browse, or paste a URL). It opens in the code editor so you can read the classes and blocks, search, and copy — it is not executed. The file is parsed entirely in your browser and never uploaded.

Q: Is a .rb file a text file?

Yes. Ruby source is plain text (UTF-8), so a `.rb` opens in any text or code editor. The syntax is what makes it Ruby, but the file is readable text.

A .rb file contains Ruby source code. Ruby is a dynamic, object-oriented language valued for expressive, readable syntax and the principle that programmer happiness matters. Its best-known application is the Ruby on Rails web framework.

In Ruby, everything is an object and blocks are a first-class idiom for iteration and callbacks. The language is interpreted (with a JIT in recent versions). Reading a .rb file is how you understand a class, gem, or Rails model.

What is a `.rb` file?

Ruby source defines classes, modules, and methods with optional type hints. It uses do…end blocks and { } lambdas, mixins via modules, and dynamic metaprogramming. Bundler manages gems; Rake is its build tool.

A .rb file is plain text (UTF-8), MIME type text/x-ruby. It runs on interpreters like MRI (the reference), JRuby, or TruffleRuby.

Ruby on Rails web applications
Scripts, automation, and DevOps tooling
Web APIs and prototype back ends
Internal tools and DSLs

How to open a `.rb` online

Open the zip viewer in a new tab, then drop your .rb onto the page — or click to browse for it, or paste a URL. The file opens in the Monaco code editor, with syntax highlighting, code folding, and find, read entirely on your device.

Drag your .rb onto the page — or click to browse, or paste a URL.
It opens immediately in the Monaco code editor, with syntax highlighting, code folding, and find. No install, no sign-up.
Read, search, or copy it. Your file never leaves your browser.

Open `.rb` without uploading

Most "open rb online" sites work by uploading your file to a server and processing it there. ZipTool does the opposite: it loads its parser once, then reads your .rb locally in the browser tab. The contents stay on your device.

You can prove that in seconds. Open the page, press F12 for DevTools, switch to the Network tab, and open your file — no request carrying the file's contents is sent. You can also turn off Wi-Fi after the page loads and the file still opens. See security and privacy for the full picture.

Frequently asked questions

How do I open a .rb file online?

Drag the .rb onto the page (or click to browse, or paste a URL). It opens in the code editor so you can read the classes and blocks, search, and copy — it is not executed. The file is parsed entirely in your browser and never uploaded.

Can I view a .rb without uploading it?

Yes. ZipTool reads the file locally in your browser tab — no upload, no server-side copy. Confirm it with DevTools (F12, Network tab) while opening the file, or by disabling Wi-Fi after the page loads and verifying the file still opens.

Is Ruby the same as Ruby on Rails?

No. Ruby is the programming language; Rails is a web framework written in Ruby. You can use Ruby for many things besides Rails (scripts, CLIs, static sites), but Rails is what made Ruby widely known.

Is a .rb file a text file?

Yes. Ruby source is plain text (UTF-8), so a .rb opens in any text or code editor. The syntax is what makes it Ruby, but the file is readable text.