list-playgrounds.md

list of playgrounds

Here are some interactive playgrounds I've found (or built) on the internet:

• CSS/HTML/JS: CodePen by Chris Coyier, Alex Vasquez, and team
• CSS/HTML/JS: JSFiddle by Oskar Krawczyk and Piotr Zalewa
• CSS/HTML/JS: flems by Rasmus Porsager (saves all state in the URL)
• DNS: Mess With DNS by Julia Evans and Marie Flanagan
• DNS: DNS lookup tool by Julia Evans
• nginx: nginx playground by Julia Evans
• varnish: fastly fiddle from fastly
• SQL: sql playground by Julia Evans
• SQLite: sqlime by Anton Zhiyanov (lets you load arbitrary SQLite databases)
• Postgres: postgres playground from Crunchydata (runs postgres in the browser!)
• regular expressions:
  • for many languages: regex101 by Firas Dib
  • for Ruby: Rubular by Michael Lovitt
  • for JS/PCRE: regexr by gskinner
  • for Python: Pythex by Gabriel Rodríguez
• Git: oh my git by blinry and bleeptrack
• Arduino / IoT: wokwi from CodeMagic
• compilers: godbolt compiler explorer by Matt Godbolt
• .NET bytecode: SharpLab by Andrey Shchekin
• Shaders: shadertoy by Inigo Quilez and Pol Jeremias

data formats

• ASN.1 certificates: ASN.1 JavaScript debugger by Lapo Luchini
• Unicode: Unicode analyzer from fontspace
• Unicode: What unicode character is this? from babelstone
• SVG: sssvg (interactive SVG reference) from fffuel (lots of other cool tools there)
• Floating point: Float Exposed by Bartosz Ciechanowski
• CBOR: CBOR playground
• cron: crontab guru from cronitor

programming languages

• official playgrounds:
  • Rust
  • Go
  • Ruby
  • Typescript
  • Haskell, C#, Scala, OCaml, Crystal
• unofficial playgrounds:
  • PHP: 3vdl by Sjon Hortensius
  • Python/JS/C/C++/Java: Python Tutor by Philip Guo
  • many languages: replit
  • others: jqplay, tryapl

Here is another one, the "official playground" for Julia: https://julialang.org/learning/tryjulia/

Here is the Docker playground play with docker:

Docker: [Play with Docker](https://labs.play-with-docker.com/) by Marcos Liljedhal and Jonathan Leibiusky

I would like to have this truly universal playground added to the list: Codapi.org. It covers programming languages, query languages, command-line tools, and probably anything you can run in a container. And it's open source.

A nice addition is the Try X in Y minutes series, based on the famous "Learn X in Y minutes" but featuring executable code snippets.

If this sounds like an ad, I apologize. I am only a happy Codapi user. (And I know the author. And I provided the Try Go in Y minutes page. But that's all, really.)