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Javascript Runtime

Path: Computer Tech/Development/Web Design/Web Stack/Javascript Runtime.mdUpdated: 2/3/2026

JavaScript runtimes provide the environment for executing JavaScript code, including an engine, event loop, and APIs.

Browser Runtimes (Client-Side)

  • Google Chrome, Edge β†’ Uses V8
  • Firefox β†’ Uses SpiderMonkey
  • Safari β†’ Uses JavaScriptCore (Nitro)
  • Opera β†’ Uses V8

Browsers provide Web APIs for interacting with the DOM, handling events, making network requests, etc.

Server-Side Runtimes

  • Node.js β†’ Uses V8, provides APIs for file system, network, process control.
  • Deno β†’ Uses V8, provides a more secure environment with TypeScript support out of the box.
  • Bun β†’ Uses JavaScriptCore (Nitro), optimized for speed and performance in server applications.

Embedded Runtimes (IoT & Mobile)

  • Electron (for desktop apps) β†’ Uses V8 (bundled with Chromium)
  • React Native β†’ Uses JavaScriptCore
  • QuickJS (lightweight runtime for embedded devices)
  • Espruino (JavaScript for microcontrollers)