- 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
- Corepack
- Crypto
- Debugger
- Deprecated APIs
- Diagnostics Channel
- DNS
- Domain
- Errors
- Events
- File system
- Globals
- HTTP
- HTTP/2
- HTTPS
- Inspector
- Internationalization
- Modules: CommonJS modules
- Modules: ECMAScript modules
- Modules:
module
API - Modules: Packages
- Net
- OS
- Path
- Performance hooks
- Policies
- Process
- Punycode
- Query strings
- Readline
- REPL
- Report
- Stream
- String decoder
- Timers
- TLS/SSL
- Trace events
- TTY
- UDP/datagram
- URL
- Utilities
- V8
- VM
- WASI
- Web Crypto API
- Web Streams API
- Worker threads
- Zlib
Node.js v16.15.0 documentation
- ► Table of contents
-
►
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
- Corepack
- Crypto
- Debugger
- Deprecated APIs
- Diagnostics Channel
- DNS
- Domain
- Errors
- Events
- File system
- Globals
- HTTP
- HTTP/2
- HTTPS
- Inspector
- Internationalization
- Modules: CommonJS modules
- Modules: ECMAScript modules
- Modules:
module
API - Modules: Packages
- Net
- OS
- Path
- Performance hooks
- Policies
- Process
- Punycode
- Query strings
- Readline
- REPL
- Report
- Stream
- String decoder
- Timers
- TLS/SSL
- Trace events
- TTY
- UDP/datagram
- URL
- Utilities
- V8
- VM
- WASI
- Web Crypto API
- Web Streams API
- Worker threads
- Zlib
- ► Other versions
- ► Options
Table of contents
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 indices are as follows:
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 Although this feature is unlikely to be removed and is still covered by semantic-versioning guarantees, it is no longer actively maintained, and other alternatives are available.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 within modules. 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 |
dgram | (2) Stable |
diagnostics_channel | (1) Experimental |
dns | (2) Stable |
domain | (0) Deprecated |
fs | (2) Stable |
http | (2) Stable |
http/2 | (2) Stable |
https | (2) Stable |
inspector | (2) Stable |
module | (2) Stable |
os | (2) Stable |
path | (2) Stable |
performance_measurement_apis | (2) Stable |
punycode | (0) Deprecated |
querystring | (3) Legacy |
readline | (2) Stable |
repl | (2) Stable |
stream | (2) Stable |
string_decoder | (2) Stable |
timers | (2) Stable |
tls_(ssl) | (2) Stable |
trace_events | (1) Experimental |
tty | (2) Stable |
url | (2) Stable |
util | (2) Stable |
vm | (2) Stable |
web_crypto_api | (1) Experimental |
web_streams_api | (1) Experimental |
webassembly_system_interface_(wasi) | (1) Experimental |
worker_threads | (2) Stable |
zlib | (2) Stable |
JSON output#
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.