JSFiddle
The original. Run and share HTML/CSS/Javascript. Includes easy access to various Javascript
libraries.
Go to jsfiddle.net
.NET Fiddle
Run and share .NET Visual Basic and C# code. Currently supports console projects.
Go to dotnetfiddle.net
sqlite3 Fiddle
Test your SQL in sqlite3 running inside the browser.
Go to sqlite.org
SQL Fiddle
Play around with database, create your schema and test SQL. Supports number of databases,
currently MariaDB, MySQL, Oracle and Oracle PLSQL, PostgreSQL, SQLite and Microsoft SQL Server
Go to sqlfiddle.com
Regex 101
Confronted with a problem, you thought "I know, I'll use regular expressions."
Now you have two problems. regex 101 to rescue!
Go to regex101
Tutorials Point
This one does not follow the official naming convention but compiles and runs code
written in various languages. Checkout the supported languages from the top menu bar.
The list is exhaustive, from Ada to Verilog via Brainf*ck and other more or less
well known languages.
Go to TutorialsPoint.com
Interactive GCC compiler
This is not a regular fiddle. Instead of letting you execute c/c++ code the interactive
compiler compiles your code and then show the assembler code. This lets you investigate
what kind of machine code is generated for certain structures with specific compiler flags.
Go to gcc.gobolt.org
ClojureScript REPL
ClojureScript is a programming language which compiles to Javascript (while regular Clojure targets JVM).
Go to REPL
Try Clojure
Clojure REPL and interactive tutorial.
Go to REPL
Logo Interpreter
Logo Interepreter by Joshua Bell runs logo programs directly in your browser. To get started,
paste some example code from the right side to the field next to "Run" button and hit run.
Go to Logo Interpreter
Brainfuck visualizer
Getting your next big thing out with Brainfuck can sometimes be a bit overwhelming. But no worries, with this tool you can easily
step through the app.
Brainfuck Debugger
FiddleSalad
Create your own web salad by mixing your choice of markup, style and programming logic. FiddleSalad supports
various languages for each part.
Go to FiddleSalad
Rust Play
Environment for writing and executing Rust programs.
Go to Rust Play
ZK Fiddle
Play around with ZK Java framework for building web applications. Create UI, write Java code. Run and Test.
Go to ZK Fiddle
Go Fiddle
Nice an clean environment for trying out Go, the statically typed language developed originally at Google.
Go to Go Fiddle
Swift Playground
Test your Swift code with various versions of Swift.
Jump to sandbox
oK
oK is a learning environment for the
K programming language.
In case your K-skills are a bit rusty, check out the
oK documentation on Github.
The thing is open source, so you can also run it on your own machine.
oK
PHP Tester
Code goes left, results come right. Easy as that to test your PHP code. PHP Tester supports multiple versions
from age old 5.x to (almost) latest and the greatest.
Run PHP Tester
Scalastie
Practise your Scala skills in the interactive playground.
This way to Scala
C++ Shell
Play around with interactive C++ shell. Supports also stdin for your "Hello, [your name here]" fiddling purposes.
C++ shell
Try ColdFusion
Back in the days ColdFusion was the thing.. In case it's still for you, this is something to try.
Try ColdFusion
ColdFusion Fiddle
This one keeps it plain and simple. Your ColdFusion code on left, results on right.
ColdFusion Fiddle
Playcode.io
Comprehensive solution for playing around with Javascript, TypeScript and various
frameworks.
Playcode
Vyxal online interpreter
Vyxal is a language developed for code golfing. And as the developer puts it,
"[It] takes the idea that conciseness comes at the cost of practicality and throws it out the window"
This site will help you develop, run and share your Vyxal creations.
Vyxal online
Sentinel playground
Sentinel is a policy as code framework from Hashicorp, embedded into enterprise versions of Consul, Nomad, Terraform and Vault.
With the playground you can learn the framework or prototype new functions and policies.
Play with Sentinel
SQLize Online
Write SQL scripts, test your queries. Support many databases, like Firebirds, MariaDB, MySQL, PostgreSQL, Oracle, Microsoft SQL Server, SQLite.
Sqlize your query
PHPize Online
Test your PHP 5.x, 7.x or 8.x code against various databases such as Oracle, MySQL and Postgres.
PHPize
DB Fiddle
Play around with many versions of Postgres, MySQL and Sqlite. Pro version available
for private fiddling needs.
Fiddle with DBs
Mongo playground
Setup your data, run your queries and check results. Easy as that!
Play with MongoDB
.NET XSLT Fiddle
Test your XSLT transformations with couple of different engines.
Translate
Try APL
"APL is a mistake, carried through to perfection" said Edsger Dijkstra. It's a
array oriented programming language, born in the 1960s and still alive.
Try APL
DuckDB Shell in browser
DuckDB is a fast in-process analytical database. And now it's running in your browser.
Import your data (for example csv files), create some queries, check the results. All of this without
uploading anything to cloud, thanks to the magic of WebAssembly.
Go to DuckDB shell
Numscript playground
Numscript is a Domain-Specific Language (DSL) designed to help you model complex financial transactions, replacing complex and error-prone custom code with easy-to-read, declarative scripts.
Numscript playground
Mermaid ASCII
Create ASCII graphics using the Mermaid language.
Mermaid ASCII
Mermaid Live
Mermaid is a language for creating diagrams and visualizations using text. With this tool you can play around with the language and try creating graphs.
Mermaid Live
Civet Playground
Civet is superset of TypeScript that works with existing tooling. It is 99% compatible with TypeScript/JavaScript, but adds certain features and syntactic sugar.
Civet playground
Starlark Playground
StarlarkStarlark is small and simple Python like language designed to be embededed in another application to provide configuration or scripting abilities.
Starlark playground