Side by side

Babel REPL vs RunJS

Both stand on code playground software. Which one you can start free with, which one lets you read the code, and what each costs once you pay.

Babel REPL

Free plan Web

Babel REPL offers a browser-based way to inspect and prototype transformations, with output and AST views. Its configuration limits and Babel’s production guidance make it more suited to learning and experimentation than production builds.

Visit Babel REPL

RunJS

Free plan LinuxMacWindows

RunJS combines quick JavaScript and TypeScript experiments with debugging, package installation, snippets, and optional AI connections. Its cross-platform desktop app and education licensing broaden its use, while buyers should review device and license terms.

Visit RunJS

The facts

	Babel REPL	RunJS
Free plan	Yes	Yes
Open source	Not published	Not published
Runs on	Web	Linux, Mac, Windows
Lowest paid plan	Not published	Free or on request
Plans published	None	2
Maker	Not published	Not published
Website	babeljs.io	runjs.app
On code playground software	#21 of 58	#25 of 58

Babel REPL: what it does well

Free and open source.
Shows input code, compiled output, and an AST pane.
Includes React, Flow, TypeScript, and Env presets.
Supports modern JavaScript and JSX transformations.
Allows custom plugins and presets.

What to know first

Does not type-check Flow or TypeScript.
Configuration files do not work in standalone use.
REPL does not support assumptions configuration or plugin options.
Babel recommends a build system for production transpilation.

RunJS: what it does well

Node.js and browser environments included
Install npm libraries without a disk project
Logpoints avoid source changes and console.log calls
Runs on Linux, macOS, and Windows
Reusable snippets support JSON import and export

What to know first

Paid licenses allow two active devices
Education license is limited to learning and teaching

Alternatives to Babel REPL Alternatives to RunJS The whole list