The JavaScript engine used in Google Chrome is V8. Developed by Google, V8 executes JavaScript and WebAssembly and is integrated into Chrome through the Chromium browser project.
V8 is an open-source engine written primarily in C++. It does more than simply interpret source code: its runtime includes bytecode interpretation and just-in-time compilation, allowing frequently executed code to be translated into optimized machine code while a program runs. This helps web applications respond quickly without requiring JavaScript authors to compile their code manually.
V8 is not the engine used by every browser. Mozilla Firefox uses SpiderMonkey, while Safari uses JavaScriptCore. V8 also operates outside browsers: it is the engine behind Node.js and is used in other runtimes and tools, including Deno and Electron-based applications. Chrome's browser engine and its JavaScript engine are separate components, so V8 should not be confused with Blink.