Is this the same as tsc?

No. Code Arena runs TypeScript by stripping types with Node. You get fast execution, not a full project compile or type-error report like tsc --noEmit.

Why did my TypeScript fail to run?

Common causes: syntax Node cannot strip, top-level await in unsupported contexts, or code that expects packages. Simplify to plain TS that compiles down to JS by removing types only.

Can I see an AST for TypeScript?

The interactive AST panel currently targets JavaScript. For typed code, open the JavaScript editor with equivalent JS, or read our Learn article on AST views.

Should I paste API keys into TypeScript snippets?

No. Runs are processed to execute your program, and share URLs can expose source. Never put secrets in playground code.

Do interfaces affect runtime?

No. Interfaces and type aliases are erased. Only values and executable statements remain after stripping.

Can I import from 'fs' or other Node modules?

Built-in modules may be available depending on the sandbox image, but network installs are not. Prefer pure logic snippets. Avoid relying on the filesystem for durable storage — sandboxes are short-lived.

What about JSX / TSX?

This playground is oriented toward .ts logic snippets, not a React app toolchain. For UI frameworks, use a dedicated template or local Vite/Next setup.

Free Typescript Online Compiler (No Signup)

Free TypeScript online compiler (no signup)

Run TypeScript snippets online with Code Arena. Add types for clarity while Node’s type-stripping path executes your program quickly — no account, no full project setup, no npm install.

How to use this editor

Open the TypeScript editor (main.ts) and start from the typed starter or paste your own code.
Add type annotations where they help — parameters, return types, and interfaces.
Press Run (or Ctrl/Cmd + Enter) to execute in the sandbox.
Read Output for console results or runtime errors.
Share a link when you want someone else to open the same snippet.
Use the tutorials below to understand stripping vs tsc before you rely on advanced TypeScript features.

Runtime notes

Runtime: Node.js 24 with --experimental-strip-types (no npm install required).
Type stripping removes type syntax before execution; it is not a full tsc check.
Features that need emit transforms (some enums, namespaces, decorators) may not run.
Network is disabled in the sandbox; keep snippets self-contained.
Path aliases and project references from a tsconfig are not applied here.
Prefer erasable TypeScript: types that disappear without changing runtime shape.

Annotate the parts that matter

In a playground, you do not need types on every local variable. Annotate function parameters, return values, and public shapes (interfaces/types). That keeps snippets readable while still catching the mistakes that hurt most.

Start from a small typed function, log the result, then gradually add a second function that consumes the first. If Run fails for a TypeScript feature, simplify toward erasable syntax.

Parameter and return types on exported-style helpers
Interfaces for objects you pass between functions
Avoid enums/namespaces/decorators in the playground
Use union types and type aliases freely — they strip cleanly

Stripping vs typechecking

Code Arena runs TypeScript by removing types and executing the remaining JavaScript. A program with a logical type mistake can still run. Your editor may show red squiggles locally; the sandbox will not act as a full typechecker.

Use Code Arena to validate runtime behavior of typed sketches. Use tsc --noEmit (or your IDE) when you need confidence that types are correct across a real project.

Migrating a JS experiment to TS

Paste working JavaScript into the TypeScript editor, rename mental model to main.ts, then add types one function at a time. Run after each step so you know whether a failure is a strip/runtime issue or just a logic bug.

If you need the AST visualization, recreate the same logic in the JavaScript editor — the interactive AST panel currently targets JavaScript.

Sharing typed demos

Share links are excellent for teaching interfaces and generics with a tiny example. Redact secrets the same way you would for JavaScript. Keep the demo under a modest size so the URL stays manageable.

FAQ

Is this the same as tsc?: No. Code Arena runs TypeScript by stripping types with Node. You get fast execution, not a full project compile or type-error report like tsc --noEmit.
Why did my TypeScript fail to run?: Common causes: syntax Node cannot strip, top-level await in unsupported contexts, or code that expects packages. Simplify to plain TS that compiles down to JS by removing types only.
Can I see an AST for TypeScript?: The interactive AST panel currently targets JavaScript. For typed code, open the JavaScript editor with equivalent JS, or read our Learn article on AST views.
Should I paste API keys into TypeScript snippets?: No. Runs are processed to execute your program, and share URLs can expose source. Never put secrets in playground code.
Do interfaces affect runtime?: No. Interfaces and type aliases are erased. Only values and executable statements remain after stripping.
Can I import from 'fs' or other Node modules?: Built-in modules may be available depending on the sandbox image, but network installs are not. Prefer pure logic snippets. Avoid relying on the filesystem for durable storage — sandboxes are short-lived.
What about JSX / TSX?: This playground is oriented toward .ts logic snippets, not a React app toolchain. For UI frameworks, use a dedicated template or local Vite/Next setup.

Example programs

Open a ready-made snippet, then run it in this editor. Browse typescript examples.

Keep learning

main.tstypescript·node24

⌘/Ctrl + Enter

Editor

Output

Ready

Run the code to see output here.

Tip: press Ctrl + Enter

Ln 1, Col 1|UTF-8|typescript