About this documentation | Node.js v22.23.2 Documentation Skip to content Node.js * About this documentation * Usage and example * Assertion testing * Asynchronous context tracking * Async hooks * Buffer * C++ addons * C/C++ addons with Node-API * C++ embedder API * Child processes * Cluster * Command-line options * Console * Crypto * Debugger * Deprecated APIs * Diagnostics Channel * DNS * Domain * Environment Variables * Errors * Events * File system * Globals * HTTP * HTTP/2 * HTTPS * Inspector * Internationalization * Modules: CommonJS modules * Modules: ECMAScript modules * Modules: node:module API * Modules: Packages * Modules: TypeScript * Net * OS * Path * Performance hooks * Permissions * Process * Punycode * Query strings * Readline * REPL * Report * Single executable applications * SQLite * Stream * String decoder * Test runner * Timers * TLS/SSL * Trace events * TTY * UDP/datagram * URL * Utilities * V8 * VM * WASI * Web Crypto API * Web Streams API * Worker threads * Zlib * Code repository and issue tracker Node.js v22.23.2 documentation * Node.js v22.23.2 * Table of contents * About this documentation * Contributing * Stability index * Stability overview * JSON output * System calls and man pages * Index * About this documentation * Usage and example * Index * Assertion testing * Asynchronous context tracking * Async hooks * Buffer * C++ addons * C/C++ addons with Node-API * C++ embedder API * Child processes * Cluster * Command-line options * Console * Crypto * Debugger * Deprecated APIs * Diagnostics Channel * DNS * Domain * Environment Variables * Errors * Events * File system * Globals * HTTP * HTTP/2 * HTTPS * Inspector * Internationalization * Modules: CommonJS modules * Modules: ECMAScript modules * Modules: node:module API * Modules: Packages * Modules: TypeScript * Net * OS * Path * Performance hooks * Permissions * Process * Punycode * Query strings * Readline * REPL * Report * Single executable applications * SQLite * Stream * String decoder * Test runner * Timers * TLS/SSL * Trace events * TTY * UDP/datagram * URL * Utilities * V8 * VM * WASI * Web Crypto API * Web Streams API * Worker threads * Zlib * Code repository and issue tracker * Other versions * 26.x * 25.x * 24.x LTS * 23.x * 22.x LTS * 21.x * 20.x * 19.x * 18.x * 17.x * 16.x * 15.x * 14.x * 13.x * 12.x * 11.x * 10.x * 9.x * 8.x * 7.x * 6.x * 5.x * 4.x * 0.12.x * 0.10.x * Options * View on single page * View as JSON * Edit on GitHub Table of contents * About this documentation * Contributing * Stability index * Stability overview * JSON output * System calls and man pages About this documentation # Welcome to the official API reference documentation for Node.js! Node.js is a JavaScript runtime built on the V8 JavaScript engine . Contributing # Report errors in this documentation in the issue tracker . See the contributing guide for directions on how to submit pull requests. Stability index # Throughout the documentation are indications of a section's stability. Some APIs are so proven and so relied upon that they are unlikely to ever change at all. Others are brand new and experimental, or known to be hazardous. The stability indexes are as follows: Stability: 0 - Deprecated. The feature may emit warnings. Backward compatibility is not guaranteed. Stability: 1 - Experimental. The feature is not subject to semantic versioning rules. Non-backward compatible changes or removal may occur in any future release. Use of the feature is not recommended in production environments. Experimental features are subdivided into stages: * 1.0 - Early development. Experimental features at this stage are unfinished and subject to substantial change. * 1.1 - Active development. Experimental features at this stage are nearing minimum viability. * 1.2 - Release candidate. Experimental features at this stage are hopefully ready to become stable. No further breaking changes are anticipated but may still occur in response to user feedback or the features' underlying specification development. We encourage user testing and feedback so that we can know that this feature is ready to be marked as stable. Experimental features leave the experimental status typically either by graduating to stable, or are removed without a deprecation cycle. Stability: 2 - Stable. Compatibility with the npm ecosystem is a high priority. Stability: 3 - Legacy. Although this feature is unlikely to be removed and is still covered by semantic versioning guarantees, it is no longer actively maintained, and other alternatives are available. Features are marked as legacy rather than being deprecated if their use does no harm, and they are widely relied upon within the npm ecosystem. Bugs found in legacy features are unlikely to be fixed. Use caution when making use of Experimental features, particularly when authoring libraries. Users may not be aware that experimental features are being used. Bugs or behavior changes may surprise users when Experimental API modifications occur. To avoid surprises, use of an Experimental feature may need a command-line flag. Experimental features may also emit a warning . Stability overview # API Stability Assert (2) Stable Async hooks (1) Experimental Asynchronous context tracking (2) Stable Buffer (2) Stable Child process (2) Stable Cluster (2) Stable Console (2) Stable Crypto (2) Stable Diagnostics Channel (2) Stable DNS (2) Stable Domain (0) Deprecated File system (2) Stable HTTP (2) Stable HTTP/2 (2) Stable HTTPS (2) Stable Inspector (2) Stable Modules: node:module API (1) .1 - Active development Modules: CommonJS modules (2) Stable Modules: TypeScript (1) .2 - Release candidate OS (2) Stable Path (2) Stable Performance measurement APIs (2) Stable Punycode (0) Deprecated Query string (2) Stable Readline (2) Stable REPL (2) Stable Single executable applications (1) .1 - Active development SQLite (1) .1 - Active development. Stream (2) Stable String decoder (2) Stable Test runner (2) Stable Timers (2) Stable TLS (SSL) (2) Stable Trace events (1) Experimental TTY (2) Stable UDP/datagram sockets (2) Stable URL (2) Stable Util (2) Stable VM (executing JavaScript) (2) Stable Web Crypto API (2) Stable Web Streams API (2) Stable WebAssembly System Interface (WASI) (1) Experimental Worker threads (2) Stable Zlib (2) Stable JSON output # Added in: v0.6.12 Every .html document has a corresponding .json document. This is for IDEs and other utilities that consume the documentation. System calls and man pages # Node.js functions which wrap a system call will document that. The docs link to the corresponding man pages which describe how the system call works. Most Unix system calls have Windows analogues. Still, behavior differences may be unavoidable.