What is glot.io and what can you do with it?

Updated

glot.io is an open-source online code playground where you can write and run code in dozens of programming languages directly in your browser. It fits quick experiments, small demos, and sharing runnable snippets: code executes in a temporary container with network access disabled, and you can save snippets as public, unlisted, or secret, then share them when you choose.

What you can do with glot.io

The site groups its capabilities into a few core actions:

  • Run code — Execute a snippet in a temporary container. Network access is disabled during execution, so code that depends on external APIs or downloads won't work as written.
  • Share snippets — Save a snippet as public, unlisted, or secret, and share it on your own terms.
  • Use editor key bindings — The editor supports Vim and Emacs key bindings if you prefer either editing style.
  • Extend language support — Because the project is open source, you can open an issue or pull request on GitHub to get a missing language added.

Supported languages

glot.io lists a broad set of languages, spanning systems, scripting, functional, and JVM languages. The published list includes:

Category Languages (as listed)
Systems / low-level Assembly, C, Cpp, D, Hare, Nim, Rust, Zig
Scripting / dynamic Ats, Bash, CoffeeScript, JavaScript, Lua, Perl, Php, Python, Raku, Ruby, TypeScript
Functional Clisp, Clojure, Elixir, Elm, Erlang, Fsharp, Guile, Haskell, Idris, Ocaml, Sac, Scala
JVM / other runtimes Groovy, Java, Kotlin, Crystal, Julia, Mercury, Nix, Pascal, Swift, Cobol

This is the list published on the site; availability can change as the open-source project evolves, so check the language selector for the current set.

How a typical session works

  1. Select a language from the language list.
  2. Write or paste your code into the editor. If you use Vim or Emacs, enable the matching key bindings.
  3. Run it. The code executes in a temporary container with network access disabled — expect a result or error output rather than any external network calls.
  4. Save and share if you want to keep it. Choose public, unlisted, or secret depending on who should be able to find it.

Things to keep in mind

  • No network during execution. Any snippet that fetches a URL, calls an API, or installs a package at runtime will fail. Write self-contained code instead.
  • Temporary containers. Execution environments are not persistent, so don't treat a run as a long-lived server or storage.
  • Sharing is a choice. Public, unlisted, and secret options let you control visibility rather than defaulting everything to public.
  • Open source means you can contribute. If a language you need is missing, the documented path is to open an issue or pull request on GitHub.

If you want a no-setup way to test a small piece of code, try a language you already know, or share a runnable example with someone, glot.io covers that. If your task needs network access, persistent state, or a full project structure, it isn't the right tool.