Which Node and which browser

The versions

Open Settings → About. It names the Node that runs Node Snippets, the Chromium that runs Web Snippets, and the V8 JavaScript engine under both.

JSpark is built on Electron 44. The versions change when an update moves JSpark to a newer Electron, so check Settings → About for the ones you have.

What Node gives you

• Node’s own behaviour. Errors and stack traces are V8’s, and setTimeout, setImmediate, process.nextTick and promises run in Node’s order.
• Your own access. A Node Run can read and write your files, use the network and start programs, as node can. See Outside Access.
• A folder to work in. A relative path, or one beside __dirname, lands in the The Working Folder.
• ESM or CommonJS. A Snippet runs as a Module or a Script. See Load Mode.
• TypeScript. JSpark compiles it to JavaScript with esbuild before Node runs it. The editor checks the types with TypeScript 5.9, inside the app.
• Code that keeps running. A server, a timer or a watcher runs until you press Stop. The time limit (5 s by default) stops only a Run that stays busy without a pause. A recording for the Timeline has a limit on its total length. See Time and memory limits.
• The Timeline. Only a Node Run can be recorded and replayed one Step at a time.

A page Run and a browser tab

A Web Snippet builds a real page, beside the editor, in a frame and a process of its own. A page that never finishes doesn't stop the app. Most of what works in a browser tab works here:

• Libraries from a CDN over https:, and import maps.
• eval and new Function, which some libraries need.
• fetch and WebSockets, to any address.
• The page keeps its state while its tab is not on screen.

These differ from a browser tab:

• Only the inline scripts and on… handlers you wrote run. One added after the page started, through innerHTML or by a library, is refused, and the console says so.
• The page is given no permissions, and nothing asks you. A request for the camera, the microphone or the clipboard is refused.
• window.open opens a tab in your web browser, only within a second of a click or key press in the page, and at most five times in one Run.