Node.js may deprecate APIs when either: (a) use of the API is considered to be unsafe, (b) an improved alternative API is available, or (c) breaking changes to the API are expected in a future major release.
Node.js utilizes three kinds of Deprecations:
A Documentation-only deprecation is one that is expressed only within the Node.js API docs. These generate no side-effects while running Node.js. Some Documentation-only deprecations trigger a runtime warning when launched with --pending-deprecation flag (or its alternative, NODE_PENDING_DEPRECATION=1 environment variable), similarly to Runtime deprecations below. Documentation-only deprecations that support that flag are explicitly labeled as such in the list of Deprecated APIs.
A Runtime deprecation will, by default, generate a process warning that will be printed to stderr the first time the deprecated API is used. When the --throw-deprecation command-line flag is used, a Runtime deprecation will cause an error to be thrown.
An End-of-Life deprecation is used when functionality is or will soon be removed from Node.js.
Occasionally, the deprecation of an API may be reversed. In such situations, this document will be updated with information relevant to the decision. However, the deprecation identifier will not be modified.
Type: Runtime
The OutgoingMessage.prototype.flush() method is deprecated. Use OutgoingMessage.prototype.flushHeaders() instead.
Type: End-of-Life
The _linklist module is deprecated. Please use a userland alternative.
Type: Runtime
The _writableState.buffer property is deprecated. Use the _writableState.getBuffer() method instead.
Type: End-of-Life
The CryptoStream.prototype.readyState property was removed.
Type: Runtime (supports --pending-deprecation)
The Buffer() function and new Buffer() constructor are deprecated due to API usability issues that can potentially lead to accidental security issues.
As an alternative, use of the following methods of constructing Buffer objects is strongly recommended:
Buffer.alloc(size[, fill[, encoding]]) - Create a Buffer with initialized memory.Buffer.allocUnsafe(size) - Create a Buffer with uninitialized memory.Buffer.allocUnsafeSlow(size) - Create a Buffer with uninitialized memory.Buffer.from(array) - Create a Buffer with a copy of array
Buffer.from(arrayBuffer[, byteOffset[, length]]) - Create a Buffer that wraps the given arrayBuffer.Buffer.from(buffer) - Create a Buffer that copies buffer.Buffer.from(string[, encoding]) - Create a Buffer that copies string.As of v10.0.0, a deprecation warning is printed at runtime when --pending-deprecation is used or when the calling code is outside node_modules in order to better target developers, rather than users.
Type: Runtime
Within the child_process module's spawn(), fork(), and exec() methods, the options.customFds option is deprecated. The options.stdio option should be used instead.
Type: End-of-Life
In an earlier version of the Node.js cluster, a boolean property with the name suicide was added to the Worker object. The intent of this property was to provide an indication of how and why the Worker instance exited. In Node.js 6.0.0, the old property was deprecated and replaced with a new worker.exitedAfterDisconnect property. The old property name did not precisely describe the actual semantics and was unnecessarily emotion-laden.
Type: Documentation-only
The constants module is deprecated. When requiring access to constants relevant to specific Node.js builtin modules, developers should instead refer to the constants property exposed by the relevant module. For instance, require('fs').constants and require('os').constants.
Type: Runtime
Use of the crypto.pbkdf2() API without specifying a digest was deprecated in Node.js 6.0 because the method defaulted to using the non-recommended 'SHA1' digest. Previously, a deprecation warning was printed. Starting in Node.js 8.0.0, calling crypto.pbkdf2() or crypto.pbkdf2Sync() with digest set to undefined will throw a TypeError.
Beginning in Node.js v11.0.0, calling these functions with digest set to null will print a deprecation warning to align with the behavior when digest is undefined.
Type: End-of-Life
The crypto.createCredentials() API was removed. Please use tls.createSecureContext() instead.
Type: End-of-Life
The crypto.Credentials class was removed. Please use tls.SecureContext instead.
Type: End-of-Life
Domain.dispose() has been removed. Recover from failed I/O actions explicitly via error event handlers set on the domain instead.
Type: End-of-Life
Calling an asynchronous function without a callback throws a TypeError in Node.js 10.0.0 onwards. (See https://github.com/nodejs/node/pull/12562.)
Type: End-of-Life
The fs.read() legacy String interface is deprecated. Use the Buffer API as mentioned in the documentation instead.
Type: End-of-Life
The fs.readSync() legacy String interface is deprecated. Use the Buffer API as mentioned in the documentation instead.
Type: Runtime
The GLOBAL and root aliases for the global property are deprecated and should no longer be used.
Type: End-of-Life
Intl.v8BreakIterator was a non-standard extension and has been removed. See Intl.Segmenter.
Type: Runtime
Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
Type: Runtime
In certain cases, require('.') may resolve outside the package directory. This behavior is deprecated and will be removed in a future major Node.js release.
Type: Runtime
The Server.connections property is deprecated. Please use the Server.getConnections() method instead.
Type: Runtime
The Server.listenFD() method is deprecated. Please use Server.listen({fd: <number>}) instead.
Type: Runtime
The os.tmpDir() API is deprecated. Please use os.tmpdir() instead.
Type: Runtime
The os.getNetworkInterfaces() method is deprecated. Please use the os.networkInterfaces property instead.
Type: End-of-Life
The REPLServer.prototype.convertToContext() API has been removed.
Type: Runtime
The sys module is deprecated. Please use the util module instead.
Type: Runtime
The util.print() API is deprecated. Please use console.log() instead.
Type: Runtime
The util.puts() API is deprecated. Please use console.log() instead.
Type: Runtime
The util.debug() API is deprecated. Please use console.error() instead.
Type: Runtime
The util.error() API is deprecated. Please use console.error() instead.
Type: Documentation-only
The SlowBuffer class is deprecated. Please use Buffer.allocUnsafeSlow(size) instead.
Type: Documentation-only
The ecdh.setPublicKey() method is now deprecated as its inclusion in the API is not useful.
Type: Documentation-only
The domain module is deprecated and should not be used.
Type: Documentation-only
The EventEmitter.listenerCount(emitter, eventName) API is deprecated. Please use emitter.listenerCount(eventName) instead.
Type: Documentation-only
The fs.exists(path, callback) API is deprecated. Please use fs.stat() or fs.access() instead.
Type: Documentation-only
The fs.lchmod(path, mode, callback) API is deprecated.
Type: Documentation-only
The fs.lchmodSync(path, mode) API is deprecated.
Type: Deprecation revoked
The fs.lchown(path, uid, gid, callback) API is deprecated.
Type: Deprecation revoked
The fs.lchownSync(path, uid, gid) API is deprecated.
Type: Documentation-only
The require.extensions property is deprecated.
Type: Documentation-only
The punycode module is deprecated. Please use a userland alternative instead.
Type: End-of-Life
The NODE_REPL_HISTORY_FILE environment variable was removed. Please use NODE_REPL_HISTORY instead.
Type: End-of-Life
The tls.CryptoStream class was removed. Please use tls.TLSSocket instead.
Type: Documentation-only
The tls.SecurePair class is deprecated. Please use tls.TLSSocket instead.
Type: Documentation-only
The util.isArray() API is deprecated. Please use Array.isArray() instead.
Type: Documentation-only
The util.isBoolean() API is deprecated.
Type: Documentation-only
The util.isBuffer() API is deprecated. Please use Buffer.isBuffer() instead.
Type: Documentation-only
The util.isDate() API is deprecated.
Type: Documentation-only
The util.isError() API is deprecated.
Type: Documentation-only
The util.isFunction() API is deprecated.
Type: Documentation-only
The util.isNull() API is deprecated.
Type: Documentation-only
The util.isNullOrUndefined() API is deprecated.
Type: Documentation-only
The util.isNumber() API is deprecated.
Type: Documentation-only
The util.isObject() API is deprecated.
Type: Documentation-only
The util.isPrimitive() API is deprecated.
Type: Documentation-only
The util.isRegExp() API is deprecated.
Type: Documentation-only
The util.isString() API is deprecated.
Type: Documentation-only
The util.isSymbol() API is deprecated.
Type: Documentation-only
The util.isUndefined() API is deprecated.
Type: Documentation-only
The util.log() API is deprecated.
Type: Documentation-only
The util._extend() API is deprecated.
Type: End-of-Life
The fs.SyncWriteStream class was never intended to be a publicly accessible API and has been removed. No alternative API is available. Please use a userland alternative.
Type: Runtime
--debug activates the legacy V8 debugger interface, which was removed as of V8 5.8. It is replaced by Inspector which is activated with --inspect instead.
Type: Documentation-only
The http module ServerResponse.prototype.writeHeader() API is deprecated. Please use ServerResponse.prototype.writeHead() instead.
The ServerResponse.prototype.writeHeader() method was never documented as an officially supported API.
Type: Runtime
The tls.createSecurePair() API was deprecated in documentation in Node.js 0.11.3. Users should use tls.Socket instead.
Type: End-of-Life
The repl module's REPL_MODE_MAGIC constant, used for replMode option, has been removed. Its behavior has been functionally identical to that of REPL_MODE_SLOPPY since Node.js 6.0.0, when V8 5.0 was imported. Please use REPL_MODE_SLOPPY instead.
The NODE_REPL_MODE environment variable is used to set the underlying replMode of an interactive node session. Its value, magic, is also removed. Please use sloppy instead.
Type: Documentation-only
The http module outgoingMessage._headers and outgoingMessage._headerNames properties are deprecated. Use one of the public methods (e.g. outgoingMessage.getHeader(), outgoingMessage.getHeaders(), outgoingMessage.getHeaderNames(), outgoingMessage.hasHeader(), outgoingMessage.removeHeader(), outgoingMessage.setHeader()) for working with outgoing headers.
The outgoingMessage._headers and outgoingMessage._headerNames properties were never documented as officially supported properties.
Type: Documentation-only
The http module OutgoingMessage.prototype._renderHeaders() API is deprecated.
The OutgoingMessage.prototype._renderHeaders property was never documented as an officially supported API.
Type: Runtime
node debug corresponds to the legacy CLI debugger which has been replaced with a V8-inspector based CLI debugger available through node inspect.
Type: End-of-Life
DebugContext has been removed in V8 and is not available in Node.js 10+.
DebugContext was an experimental API.
Type: End-of-Life
async_hooks.currentId() was renamed to async_hooks.executionAsyncId() for clarity.
This change was made while async_hooks was an experimental API.
Type: End-of-Life
async_hooks.triggerId() was renamed to async_hooks.triggerAsyncId() for clarity.
This change was made while async_hooks was an experimental API.
Type: End-of-Life
async_hooks.AsyncResource.triggerId() was renamed to async_hooks.AsyncResource.triggerAsyncId() for clarity.
This change was made while async_hooks was an experimental API.
Type: End-of-Life
Accessing several internal, undocumented properties of net.Server instances with inappropriate names is deprecated.
As the original API was undocumented and not generally useful for non-internal code, no replacement API is provided.
Type: Runtime
The REPLServer.bufferedCommand property was deprecated in favor of REPLServer.clearBufferedCommand().
Type: Runtime
REPLServer.parseREPLKeyword() was removed from userland visibility.
Type: Runtime
tls.parseCertString() is a trivial parsing helper that was made public by mistake. This function can usually be replaced with:
const querystring = require('querystring');
querystring.parse(str, '\n', '=');
This function is not completely equivalent to querystring.parse(). One difference is that querystring.parse() does url decoding:
> querystring.parse('%E5%A5%BD=1', '\n', '=');
{ '好': '1' }
> tls.parseCertString('%E5%A5%BD=1');
{ '%E5%A5%BD': '1' }
Type: Runtime
Module._debug() is deprecated.
The Module._debug() function was never documented as an officially supported API.
Type: Runtime
REPLServer.turnOffEditorMode() was removed from userland visibility.
Type: End-of-Life
Using a property named inspect on an object to specify a custom inspection function for util.inspect() is deprecated. Use util.inspect.custom instead. For backward compatibility with Node.js prior to version 6.4.0, both may be specified.
Type: Documentation-only
The internal path._makeLong() was not intended for public use. However, userland modules have found it useful. The internal API is deprecated and replaced with an identical, public path.toNamespacedPath() method.
Type: Runtime
fs.truncate() fs.truncateSync() usage with a file descriptor is deprecated. Please use fs.ftruncate() or fs.ftruncateSync() to work with file descriptors.
Type: Runtime
REPLServer.prototype.memory() is only necessary for the internal mechanics of the REPLServer itself. Do not use this function.
Type: End-of-Life.
The ecdhCurve option to tls.createSecureContext() and tls.TLSSocket could be set to false to disable ECDH entirely on the server only. This mode was deprecated in preparation for migrating to OpenSSL 1.1.0 and consistency with the client and is now unsupported. Use the ciphers parameter instead.
Type: Runtime
Since Node.js versions 4.4.0 and 5.2.0, several modules only intended for internal usage are mistakenly exposed to user code through require(). These modules are:
v8/tools/codemapv8/tools/consarrayv8/tools/csvparserv8/tools/logreaderv8/tools/profile_viewv8/tools/profilev8/tools/SourceMapv8/tools/splaytreev8/tools/tickprocessor-driverv8/tools/tickprocessornode-inspect/lib/_inspect (from 7.6.0)node-inspect/lib/internal/inspect_client (from 7.6.0)node-inspect/lib/internal/inspect_repl (from 7.6.0)The v8/* modules do not have any exports, and if not imported in a specific order would in fact throw errors. As such there are virtually no legitimate use cases for importing them through require().
On the other hand, node-inspect may be installed locally through a package manager, as it is published on the npm registry under the same name. No source code modification is necessary if that is done.
Type: End-of-Life
The AsyncHooks Sensitive API was never documented and had various minor issues. (See https://github.com/nodejs/node/issues/15572.) Use the AsyncResource API instead.
Type: End-of-Life
runInAsyncIdScope doesn't emit the 'before' or 'after' event and can thus cause a lot of issues. See https://github.com/nodejs/node/issues/14328 for more details.
Type: Documentation-only
Importing assert directly is not recommended as the exposed functions will use loose equality checks. Use require('assert').strict instead. The API is the same as the legacy assert but it will always use strict equality checks.
Type: End-of-Life
Node.js used to support all GCM authentication tag lengths which are accepted by OpenSSL when calling decipher.setAuthTag(). Beginning with node v11.0.0, only authentication tag lengths of 128, 120, 112, 104, 96, 64, and 32 bits are allowed. Authentication tags whose length is not included in this list are considered invalid in compliance with NIST SP 800-38D.
Type: Runtime
The crypto.DEFAULT_ENCODING property is deprecated.
Type: Documentation-only
Assigning properties to the top-level this as an alternative to module.exports is deprecated. Developers should use exports or module.exports instead.
Type: Documentation-only
The crypto.fips property is deprecated. Please use crypto.setFips() and crypto.getFips() instead.
Type: Runtime
Using assert.fail() with more than one argument is deprecated. Use assert.fail() with only one argument or use a different assert module method.
Type: Runtime
timers.enroll() is deprecated. Please use the publicly documented setTimeout() or setInterval() instead.
Type: Runtime
timers.unenroll() is deprecated. Please use the publicly documented clearTimeout() or clearInterval() instead.
Type: Runtime
Users of MakeCallback that add the domain property to carry context, should start using the async_context variant of MakeCallback or CallbackScope, or the high-level AsyncResource class.
Type: Runtime
The embedded API provided by AsyncHooks exposes .emitBefore() and .emitAfter() methods which are very easy to use incorrectly which can lead to unrecoverable errors.
Use asyncResource.runInAsyncScope() API instead which provides a much safer, and more convenient, alternative. See https://github.com/nodejs/node/pull/18513 for more details.
Type: Compile-time
Certain versions of node::MakeCallback APIs available to native modules are deprecated. Please use the versions of the API that accept an async_context parameter.
Type: Runtime
process.assert() is deprecated. Please use the assert module instead.
This was never a documented feature.
Type: End-of-Life
The --with-lttng compile-time option has been removed.
Type: End-of-Life
Using the noAssert argument has no functionality anymore. All input is going to be verified, no matter if it is set to true or not. Skipping the verification could lead to hard to find errors and crashes.
Type: Documentation-only (supports --pending-deprecation)
Using process.binding() in general should be avoided. The type checking methods in particular can be replaced by using util.types.
This deprecation has been superseded by the deprecation of the process.binding() API (DEP0111).
Type: Documentation-only (supports --pending-deprecation)
When assigning a non-string property to process.env, the assigned value is implicitly converted to a string. This behavior is deprecated if the assigned value is not a string, boolean, or number. In the future, such assignment may result in a thrown error. Please convert the property to a string before assigning it to process.env.
Type: End-of-Life
decipher.finaltol() has never been documented and was an alias for decipher.final(). This API has been removed, and it is recommended to use decipher.final() instead.
Type: Runtime
Using crypto.createCipher() and crypto.createDecipher() should be avoided as they use a weak key derivation function (MD5 with no salt) and static initialization vectors. It is recommended to derive a key using crypto.pbkdf2() or crypto.scrypt() and to use crypto.createCipheriv() and crypto.createDecipheriv() to obtain the Cipher and Decipher objects respectively.
Type: End-of-Life
This was an undocumented helper function not intended for use outside Node.js core and obsoleted by the removal of NPN (Next Protocol Negotiation) support.
Type: Runtime
Deprecated alias for zlib.bytesWritten. This original name was chosen because it also made sense to interpret the value as the number of bytes read by the engine, but is inconsistent with other streams in Node.js that expose values under these names.
Type: Runtime
Some previously supported (but strictly invalid) URLs were accepted through the http.request(), http.get(), https.request(), https.get(), and tls.checkServerIdentity() APIs because those were accepted by the legacy url.parse() API. The mentioned APIs now use the WHATWG URL parser that requires strictly valid URLs. Passing an invalid URL is deprecated and support will be removed in the future.
Type: Documentation-only
The produceCachedData option is deprecated. Use script.createCachedData() instead.
Type: Documentation-only
The process.binding() API is intended for use by Node.js internal code only. Use of process.binding() by userland code is unsupported.
Type: Runtime
The dgram module previously contained several APIs that were never meant to accessed outside of Node.js core: Socket.prototype._handle, Socket.prototype._receiving, Socket.prototype._bindState, Socket.prototype._queue, Socket.prototype._reuseAddr, Socket.prototype._healthCheck(), Socket.prototype._stopReceiving(), and dgram._createSocketHandle().
Type: Runtime
With the current crypto API, having Cipher.setAuthTag() and Decipher.getAuthTag() is not helpful and both functions will throw an error when called. They have never been documented and will be removed in a future release.
Type: Runtime
The crypto._toBuf() function was not designed to be used by modules outside of Node.js core and will be removed in the future.
Type: Documentation-only (supports --pending-deprecation)
In recent versions of Node.js, there is no difference between crypto.randomBytes() and crypto.pseudoRandomBytes(). The latter is deprecated along with the undocumented aliases crypto.prng() and crypto.rng() in favor of crypto.randomBytes() and may be removed in a future release.
Type: Documentation-only
The Legacy URL API is deprecated. This includes url.format(), url.parse(), url.resolve(), and the legacy urlObject. Please use the WHATWG URL API instead.
Type: Runtime
Previous versions of Node.js exposed handles to internal native objects through the _handle property of the Cipher, Decipher, DiffieHellman, DiffieHellmanGroup, ECDH, Hash, Hmac, Sign, and Verify classes. Using the _handle property to access the native object is deprecated because improper use of the native object can lead to crashing the application.
Type: Runtime
Previous versions of Node.js supported dns.lookup() with a falsy hostname like dns.lookup(false) due to backward compatibility. This behavior is undocumented and is thought to be unused in real world apps. It will become an error in future versions of Node.js.
Type: Documentation-only (supports --pending-deprecation)
Directly calling process.binding('uv').errname(<val>) is deprecated. Please make sure to use util.getSystemErrorName() instead.
Type: Runtime
Windows Performance Counter support has been removed from Node.js. The undocumented COUNTER_NET_SERVER_CONNECTION(), COUNTER_NET_SERVER_CONNECTION_CLOSE(), COUNTER_HTTP_SERVER_REQUEST(), COUNTER_HTTP_SERVER_RESPONSE(), COUNTER_HTTP_CLIENT_REQUEST(), and COUNTER_HTTP_CLIENT_RESPONSE() functions have been deprecated.
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https://nodejs.org/dist/latest-v11.x/docs/api/deprecations.html