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# Deprecated APIs#

Node.js may deprecate APIs for any of the following reasons:

- Use of the API is unsafe.
- An improved alternative API is available.
- Breaking changes to the API are expected in a future major release.

Node.js utilizes three kinds of Deprecations:

- Documentation-only
- Runtime
- End-of-Life

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.

## Revoking deprecations#

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.

## List of Deprecated APIs#

### DEP0001: http.OutgoingMessage.prototype.flush#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v1.6.0 | Runtime deprecation.

Type: Runtime

The `OutgoingMessage.prototype.flush()` method is deprecated. Use `OutgoingMessage.prototype.flushHeaders()` instead.

### DEP0002: require('_linklist')#

History

Version | Changes
--- | ---
v8.0.0 | End-of-Life.
v6.12.0 | A deprecation code has been assigned.
v5.0.0 | Runtime deprecation.

Type: End-of-Life

The `_linklist` module is deprecated. Please use a userland alternative.

### DEP0003: _writableState.buffer#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.11.15 | Runtime deprecation.

Type: Runtime

The `_writableState.buffer` property is deprecated. Use the `_writableState.getBuffer()` method instead.

### DEP0004: CryptoStream.prototype.readyState#

History

Version | Changes
--- | ---
v10.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
0.4.0 | Documentation-only deprecation.

Type: End-of-Life

The `CryptoStream.prototype.readyState` property was removed.

### DEP0005: Buffer() constructor#

History

Version | Changes
--- | ---
v10.0.0 | Runtime deprecation.
v6.12.0 | A deprecation code has been assigned.
v6.0.0 | Documentation-only deprecation.

Type: Runtime (supports `--pending-deprecation`)

The `Buffer()` function and `new Buffer()` constructor are deprecated due to API usability issues that can lead to accidental security issues.

As an alternative, use one of the following methods of constructing `Buffer` objects:

- `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.

### DEP0006: child_process options.customFds#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.11.14 | Runtime deprecation.
v0.5.11 | Documentation-only deprecation.

Type: End-of-Life

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.

### DEP0007: Replace cluster worker.suicide with worker.exitedAfterDisconnect#

History

Version | Changes
--- | ---
v9.0.0 | End-of-Life.
v7.0.0 | Runtime deprecation.
v6.12.0 | A deprecation code has been assigned.
v6.0.0 | Documentation-only deprecation.

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.

### DEP0008: require('constants')#

History

Version | Changes
--- | ---
v6.12.0 | A deprecation code has been assigned.
v6.3.0 | Documentation-only deprecation.

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`.

### DEP0009: crypto.pbkdf2 without digest#

History

Version | Changes
--- | ---
v11.0.0 | Runtime deprecation (for `digest === null`).
v8.0.0 | End-of-Life (for `digest === undefined`).
v6.12.0 | A deprecation code has been assigned.
v6.0.0 | Runtime deprecation (for `digest === undefined`).

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`.

### DEP0010: crypto.createCredentials#

History

Version | Changes
--- | ---
v11.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.11.13 | Runtime deprecation.

Type: End-of-Life

The `crypto.createCredentials()` API was removed. Please use `tls.createSecureContext()` instead.

### DEP0011: crypto.Credentials#

History

Version | Changes
--- | ---
v11.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.11.13 | Runtime deprecation.

Type: End-of-Life

The `crypto.Credentials` class was removed. Please use `tls.SecureContext` instead.

### DEP0012: Domain.dispose#

History

Version | Changes
--- | ---
v9.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.11.7 | Runtime deprecation.

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.

### DEP0013: fs asynchronous function without callback#

History

Version | Changes
--- | ---
v10.0.0 | End-of-Life.
v7.0.0 | Runtime deprecation.

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.

### DEP0014: fs.read legacy String interface#

History

Version | Changes
--- | ---
v8.0.0 | End-of-Life.
v6.0.0 | Runtime deprecation.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.1.96 | Documentation-only deprecation.

Type: End-of-Life

The `fs.read()` legacy `String` interface is deprecated. Use the `Buffer` API as mentioned in the documentation instead.

### DEP0015: fs.readSync legacy String interface#

History

Version | Changes
--- | ---
v8.0.0 | End-of-Life.
v6.0.0 | Runtime deprecation.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.1.96 | Documentation-only deprecation.

Type: End-of-Life

The `fs.readSync()` legacy `String` interface is deprecated. Use the `Buffer` API as mentioned in the documentation instead.

### DEP0016: GLOBAL/root#

History

Version | Changes
--- | ---
v6.12.0 | A deprecation code has been assigned.
v6.0.0 | Runtime deprecation.

Type: Runtime

The `GLOBAL` and `root` aliases for the `global` property are deprecated and should no longer be used.

### DEP0017: Intl.v8BreakIterator#

History

Version | Changes
--- | ---
v9.0.0 | End-of-Life.
v7.0.0 | Runtime deprecation.

Type: End-of-Life

`Intl.v8BreakIterator` was a non-standard extension and has been removed. See `Intl.Segmenter`.

### DEP0018: Unhandled promise rejections#

History

Version | Changes
--- | ---
v7.0.0 | Runtime deprecation.

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.

### DEP0019: require('.') resolved outside directory#

History

Version | Changes
--- | ---
v12.0.0 | Removed functionality.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v1.8.1 | Runtime deprecation.

Type: End-of-Life

In certain cases, `require('.')` could resolve outside the package directory. This behavior has been removed.

### DEP0020: Server.connections#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.9.7 | Runtime deprecation.

Type: Runtime

The `Server.connections` property is deprecated. Please use the `Server.getConnections()` method instead.

### DEP0021: Server.listenFD#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.7.12 | Runtime deprecation.

Type: End-of-Life

The `Server.listenFD()` method was deprecated and removed. Please use `Server.listen({fd: <number>})` instead.

### DEP0022: os.tmpDir()#

History

Version | Changes
--- | ---
v7.0.0 | Runtime deprecation.

Type: Runtime

The `os.tmpDir()` API is deprecated. Please use `os.tmpdir()` instead.

### DEP0023: os.getNetworkInterfaces()#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.6.0 | Runtime deprecation.

Type: End-of-Life

The `os.getNetworkInterfaces()` method is deprecated. Please use the `os.networkInterfaces()` method instead.

### DEP0024: REPLServer.prototype.convertToContext()#

History

Version | Changes
--- | ---
v9.0.0 | End-of-Life.
v7.0.0 | Runtime deprecation.

Type: End-of-Life

The `REPLServer.prototype.convertToContext()` API has been removed.

### DEP0025: require('sys')#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v1.0.0 | Runtime deprecation.

Type: Runtime

The `sys` module is deprecated. Please use the `util` module instead.

### DEP0026: util.print()#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.11.3 | Runtime deprecation.

Type: End-of-Life

`util.print()` has been removed. Please use `console.log()` instead.

### DEP0027: util.puts()#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.11.3 | Runtime deprecation.

Type: End-of-Life

`util.puts()` has been removed. Please use `console.log()` instead.

### DEP0028: util.debug()#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.11.3 | Runtime deprecation.

Type: End-of-Life

`util.debug()` has been removed. Please use `console.error()` instead.

### DEP0029: util.error()#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.11.3 | Runtime deprecation.

Type: End-of-Life

`util.error()` has been removed. Please use `console.error()` instead.

### DEP0030: SlowBuffer#

History

Version | Changes
--- | ---
v6.12.0 | A deprecation code has been assigned.
v6.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `SlowBuffer` class is deprecated. Please use `Buffer.allocUnsafeSlow(size)` instead.

### DEP0031: ecdh.setPublicKey()#

History

Version | Changes
--- | ---
v6.12.0 | A deprecation code has been assigned.
v5.2.0 | Documentation-only deprecation.

Type: Documentation-only

The `ecdh.setPublicKey()` method is now deprecated as its inclusion in the API is not useful.

### DEP0032: domain module#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v1.4.2 | Documentation-only deprecation.

Type: Documentation-only

The `domain` module is deprecated and should not be used.

### DEP0033: EventEmitter.listenerCount()#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.2.0 | Documentation-only deprecation.

Type: Documentation-only

The `EventEmitter.listenerCount(emitter, eventName)` API is deprecated. Please use `emitter.listenerCount(eventName)` instead.

### DEP0034: fs.exists(path, callback)[src]#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v1.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `fs.exists(path, callback)` API is deprecated. Please use `fs.stat()` or `fs.access()` instead.

### DEP0035: fs.lchmod(path, mode, callback)#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.4.7 | Documentation-only deprecation.

Type: Documentation-only

The `fs.lchmod(path, mode, callback)` API is deprecated.

### DEP0036: fs.lchmodSync(path, mode)#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.4.7 | Documentation-only deprecation.

Type: Documentation-only

The `fs.lchmodSync(path, mode)` API is deprecated.

### DEP0037: fs.lchown(path, uid, gid, callback)[src]#

History

Version | Changes
--- | ---
v10.6.0 | Deprecation revoked.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.4.7 | Documentation-only deprecation.

Type: Deprecation revoked

The `fs.lchown(path, uid, gid, callback)` API was deprecated. The deprecation was revoked because the requisite supporting APIs were added in libuv.

### DEP0038: fs.lchownSync(path, uid, gid)[src]#

History

Version | Changes
--- | ---
v10.6.0 | Deprecation revoked.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.4.7 | Documentation-only deprecation.

Type: Deprecation revoked

The `fs.lchownSync(path, uid, gid)` API was deprecated. The deprecation was revoked because the requisite supporting APIs were added in libuv.

### DEP0039: require.extensions#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.10.6 | Documentation-only deprecation.

Type: Documentation-only

The `require.extensions` property is deprecated.

### DEP0040: punycode module#

History

Version | Changes
--- | ---
v7.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `punycode` module is deprecated. Please use a userland alternative instead.

### DEP0041: NODE_REPL_HISTORY_FILE environment variable#

History

Version | Changes
--- | ---
v10.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.0.0 | Documentation-only deprecation.

Type: End-of-Life

The `NODE_REPL_HISTORY_FILE` environment variable was removed. Please use `NODE_REPL_HISTORY` instead.

### DEP0042: tls.CryptoStream#

History

Version | Changes
--- | ---
v10.0.0 | End-of-Life.
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v0.11.3 | Documentation-only deprecation.

Type: End-of-Life

The `tls.CryptoStream` class was removed. Please use `tls.TLSSocket` instead.

### DEP0043: tls.SecurePair#

History

Version | Changes
--- | ---
v8.0.0 | Runtime deprecation.
v6.12.0 | A deprecation code has been assigned.
v6.0.0 | Documentation-only deprecation.
v0.11.15 | Deprecation revoked.
v0.11.3 | Runtime deprecation.

Type: Documentation-only

The `tls.SecurePair` class is deprecated. Please use `tls.TLSSocket` instead.

### DEP0044: util.isArray()#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isArray()` API is deprecated. Please use `Array.isArray()` instead.

### DEP0045: util.isBoolean()[src]#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isBoolean()` API is deprecated.

### DEP0046: util.isBuffer()#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isBuffer()` API is deprecated. Please use `Buffer.isBuffer()` instead.

### DEP0047: util.isDate()#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isDate()` API is deprecated.

### DEP0048: util.isError()[src]#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isError()` API is deprecated.

### DEP0049: util.isFunction()[src]#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isFunction()` API is deprecated.

### DEP0050: util.isNull()[src]#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isNull()` API is deprecated.

### DEP0051: util.isNullOrUndefined()[src]#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isNullOrUndefined()` API is deprecated.

### DEP0052: util.isNumber()[src]#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isNumber()` API is deprecated.

### DEP0053 util.isObject()#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isObject()` API is deprecated.

### DEP0054: util.isPrimitive()[src]#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isPrimitive()` API is deprecated.

### DEP0055: util.isRegExp()#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isRegExp()` API is deprecated.

### DEP0056: util.isString()[src]#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isString()` API is deprecated.

### DEP0057: util.isSymbol()[src]#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isSymbol()` API is deprecated.

### DEP0058: util.isUndefined()[src]#

History

Version | Changes
--- | ---
v4.8.6, v6.12.0 | A deprecation code has been assigned.
v3.3.1, v4.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.isUndefined()` API is deprecated.

### DEP0059: util.log()[src]#

History

Version | Changes
--- | ---
v6.12.0 | A deprecation code has been assigned.
v6.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util.log()` API is deprecated.

### DEP0060: util._extend()#

History

Version | Changes
--- | ---
v6.12.0 | A deprecation code has been assigned.
v6.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `util._extend()` API is deprecated.

### DEP0061: fs.SyncWriteStream#

History

Version | Changes
--- | ---
v11.0.0 | End-of-Life.
v8.0.0 | Runtime deprecation.
v7.0.0 | Documentation-only deprecation.

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.

### DEP0062: node --debug#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v8.0.0 | Runtime deprecation.

Type: End-of-Life

`--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.

### DEP0063: ServerResponse.prototype.writeHeader()#

History

Version | Changes
--- | ---
v8.0.0 | Documentation-only deprecation.

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.

### DEP0064: tls.createSecurePair()#

History

Version | Changes
--- | ---
v8.0.0 | Runtime deprecation.
v6.12.0 | A deprecation code has been assigned.
v6.0.0 | Documentation-only deprecation.
v0.11.15 | Deprecation revoked.
v0.11.3 | Runtime deprecation.

Type: Runtime

The `tls.createSecurePair()` API was deprecated in documentation in Node.js 0.11.3. Users should use `tls.Socket` instead.

### DEP0065: repl.REPL_MODE_MAGIC and NODE_REPL_MODE=magic#

History

Version | Changes
--- | ---
v10.0.0 | End-of-Life.
v8.0.0 | Documentation-only deprecation.

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.

### DEP0066: OutgoingMessage.prototype._headers, OutgoingMessage.prototype._headerNames#

History

Version | Changes
--- | ---
v12.0.0 | Runtime deprecation.
v8.0.0 | Documentation-only deprecation.

Type: Runtime

The `http` module `OutgoingMessage.prototype._headers` and `OutgoingMessage.prototype._headerNames` properties are deprecated. Use one of the public methods (e.g. `OutgoingMessage.prototype.getHeader()`, `OutgoingMessage.prototype.getHeaders()`, `OutgoingMessage.prototype.getHeaderNames()`, `OutgoingMessage.prototype.hasHeader()`, `OutgoingMessage.prototype.removeHeader()`, `OutgoingMessage.prototype.setHeader()`) for working with outgoing headers.

The `OutgoingMessage.prototype._headers` and `OutgoingMessage.prototype._headerNames` properties were never documented as officially supported properties.

### DEP0067: OutgoingMessage.prototype._renderHeaders#

History

Version | Changes
--- | ---
v8.0.0 | Documentation-only deprecation.

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.

### DEP0068: node debug#

History

Version | Changes
--- | ---
v8.0.0 | Runtime deprecation.

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`.

### DEP0069: vm.runInDebugContext(string)#

History

Version | Changes
--- | ---
v10.0.0 | End-of-Life.
v9.0.0 | Runtime deprecation.
v8.0.0 | Documentation-only deprecation.

Type: End-of-Life

DebugContext has been removed in V8 and is not available in Node.js 10+.

DebugContext was an experimental API.

### DEP0070: async_hooks.currentId()#

History

Version | Changes
--- | ---
v9.0.0 | End-of-Life.
v8.2.0 | Runtime deprecation.

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.

### DEP0071: async_hooks.triggerId()#

History

Version | Changes
--- | ---
v9.0.0 | End-of-Life.
v8.2.0 | Runtime deprecation.

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.

### DEP0072: async_hooks.AsyncResource.triggerId()#

History

Version | Changes
--- | ---
v9.0.0 | End-of-Life.
v8.2.0 | Runtime deprecation.

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.

### DEP0073: Several internal properties of net.Server#

History

Version | Changes
--- | ---
v10.0.0 | End-of-Life.
v9.0.0 | Runtime deprecation.

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.

### DEP0074: REPLServer.bufferedCommand#

History

Version | Changes
--- | ---
v9.0.0 | Runtime deprecation.

Type: Runtime

The `REPLServer.bufferedCommand` property was deprecated in favor of `REPLServer.clearBufferedCommand()`.

### DEP0075: REPLServer.parseREPLKeyword()#

History

Version | Changes
--- | ---
v9.0.0 | Runtime deprecation.

Type: Runtime

`REPLServer.parseREPLKeyword()` was removed from userland visibility.

### DEP0076: tls.parseCertString()#

History

Version | Changes
--- | ---
v9.0.0 | Runtime deprecation.
v8.6.0 | Documentation-only deprecation.

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' }

### DEP0077: Module._debug()#

History

Version | Changes
--- | ---
v9.0.0 | Runtime deprecation.

Type: Runtime

`Module._debug()` is deprecated.

The `Module._debug()` function was never documented as an officially supported API.

### DEP0078: REPLServer.turnOffEditorMode()#

History

Version | Changes
--- | ---
v9.0.0 | Runtime deprecation.

Type: Runtime

`REPLServer.turnOffEditorMode()` was removed from userland visibility.

### DEP0079: Custom inspection function on Objects via .inspect()#

History

Version | Changes
--- | ---
v11.0.0 | End-of-Life.
v10.0.0 | Runtime deprecation.
v8.7.0 | Documentation-only deprecation.

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.

### DEP0080: path._makeLong()#

History

Version | Changes
--- | ---
v9.0.0 | Documentation-only deprecation.

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.

### DEP0081: fs.truncate() using a file descriptor[src]#

History

Version | Changes
--- | ---
v9.0.0 | Runtime deprecation.

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.

### DEP0082: REPLServer.prototype.memory()#

History

Version | Changes
--- | ---
v9.0.0 | Runtime deprecation.

Type: Runtime

`REPLServer.prototype.memory()` is only necessary for the internal mechanics of the `REPLServer` itself. Do not use this function.

### DEP0083: Disabling ECDH by setting ecdhCurve to false#

History

Version | Changes
--- | ---
v10.0.0 | End-of-Life.
v9.2.0 | Runtime deprecation.

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.

### DEP0084: requiring bundled internal dependencies#

History

Version | Changes
--- | ---
v12.0.0 | This functionality has been removed.
v10.0.0 | Runtime deprecation.

Type: End-of-Life

Since Node.js versions 4.4.0 and 5.2.0, several modules only intended for internal usage were mistakenly exposed to user code through `require()`. These modules were:

- `v8/tools/codemap`
- `v8/tools/consarray`
- `v8/tools/csvparser`
- `v8/tools/logreader`
- `v8/tools/profile_view`
- `v8/tools/profile`
- `v8/tools/SourceMap`
- `v8/tools/splaytree`
- `v8/tools/tickprocessor-driver`
- `v8/tools/tickprocessor`
- `node-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.

### DEP0085: AsyncHooks Sensitive API#

History

Version | Changes
--- | ---
10.0.0 | End-of-Life.
v8.10.0, v9.4.0 | Runtime deprecation.

Type: End-of-Life

The AsyncHooks Sensitive API was never documented and had various minor issues. Use the `AsyncResource` API instead. See https://github.com/nodejs/node/issues/15572.

### DEP0086: Remove runInAsyncIdScope#

History

Version | Changes
--- | ---
10.0.0 | End-of-Life.
v8.10.0, v9.4.0 | Runtime deprecation.

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.

### DEP0089: require('assert')#

History

Version | Changes
--- | ---
v9.9.0, v10.0.0 | Documentation-only deprecation.

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.

### DEP0090: Invalid GCM authentication tag lengths#

History

Version | Changes
--- | ---
v11.0.0 | End-of-Life.
v10.0.0 | Runtime deprecation.

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.js v11.0.0, only authentication tag lengths of 128, 120, 112, 104, 96, 64, and 32 bits are allowed. Authentication tags of other lengths are invalid per NIST SP 800-38D.

### DEP0091: crypto.DEFAULT_ENCODING#

History

Version | Changes
--- | ---
v10.0.0 | Runtime deprecation.

Type: Runtime

The `crypto.DEFAULT_ENCODING` property is deprecated.

### DEP0092: Top-level `this` bound to `module.exports`#

History

Version | Changes
--- | ---
v10.0.0 | Documentation-only deprecation.

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.

### DEP0093: crypto.fips is deprecated and replaced.#

History

Version | Changes
--- | ---
v10.0.0 | Documentation-only deprecation.

Type: Documentation-only

The `crypto.fips` property is deprecated. Please use `crypto.setFips()` and `crypto.getFips()` instead.

### DEP0094: Using `assert.fail()` with more than one argument.#

History

Version | Changes
--- | ---
v10.0.0 | Runtime deprecation.

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.

### DEP0095: timers.enroll()#

History

Version | Changes
--- | ---
v10.0.0 | Runtime deprecation.

Type: Runtime

`timers.enroll()` is deprecated. Please use the publicly documented `setTimeout()` or `setInterval()` instead.

### DEP0096: timers.unenroll()#

History

Version | Changes
--- | ---
v10.0.0 | Runtime deprecation.

Type: Runtime

`timers.unenroll()` is deprecated. Please use the publicly documented `clearTimeout()` or `clearInterval()` instead.

### DEP0097: MakeCallback with domain property#

History

Version | Changes
--- | ---
v10.0.0 | Runtime deprecation.

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.

### DEP0098: AsyncHooks Embedder AsyncResource.emitBefore and AsyncResource.emitAfter APIs#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life
v8.12.0, v9.6.0, v10.0.0 | Runtime deprecation.

Type: End-of-Life

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.

### DEP0099: async context-unaware node::MakeCallback C++ APIs#

History

Version | Changes
--- | ---
v10.0.0 | Compile-time deprecation.

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.

### DEP0100: process.assert()#

History

Version | Changes
--- | ---
v10.0.0 | Runtime deprecation.
v0.3.7 | Documentation-only deprecation.

Type: Runtime

`process.assert()` is deprecated. Please use the `assert` module instead.

This was never a documented feature.

### DEP0101: --with-lttng#

History

Version | Changes
--- | ---
v10.0.0 | End-of-Life.

Type: End-of-Life

The `--with-lttng` compile-time option has been removed.

### DEP0102: Using `noAssert` in Buffer#(read|write) operations.#

History

Version | Changes
--- | ---
v10.0.0 | End-of-Life.

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.

### DEP0103: process.binding('util').is[...] typechecks#

History

Version | Changes
--- | ---
v10.9.0 | Superseded by DEP0111.
v10.0.0 | Documentation-only deprecation.

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).

### DEP0104: process.env string coercion#

History

Version | Changes
--- | ---
v10.0.0 | Documentation-only deprecation.

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`.

### DEP0105: decipher.finaltol#

History

Version | Changes
--- | ---
v11.0.0 | End-of-Life.
v10.0.0 | Runtime deprecation.

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.

### DEP0106: crypto.createCipher and crypto.createDecipher#

History

Version | Changes
--- | ---
v11.0.0 | Runtime deprecation.
v10.0.0 | Documentation-only deprecation.

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.

### DEP0107: tls.convertNPNProtocols()#

History

Version | Changes
--- | ---
v11.0.0 | End-of-Life.
v10.0.0 | Runtime deprecation.

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.

### DEP0108: zlib.bytesRead#

History

Version | Changes
--- | ---
v11.0.0 | Runtime deprecation.
v10.0.0 | Documentation-only deprecation.

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.

### DEP0109: http, https, and tls support for invalid URLs#

History

Version | Changes
--- | ---
v11.0.0 | Runtime deprecation.

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.

### DEP0110: vm.Script cached data#

History

Version | Changes
--- | ---
v10.6.0 | Documentation-only deprecation.

Type: Documentation-only

The `produceCachedData` option is deprecated. Use `script.createCachedData()` instead.

### DEP0111: process.binding()#

History

Version | Changes
--- | ---
v11.12.0 | Added support for `--pending-deprecation`.
v10.9.0 | Documentation-only deprecation.

Type: Documentation-only (supports `--pending-deprecation`)

`process.binding()` is for use by Node.js internal code only.

### DEP0112: dgram private APIs#

History

Version | Changes
--- | ---
v11.0.0 | Runtime deprecation.

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()`.

### DEP0113: Cipher.setAuthTag(), Decipher.getAuthTag()#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v11.0.0 | Runtime deprecation.

Type: End-of-Life

`Cipher.setAuthTag()` and `Decipher.getAuthTag()` are no longer available. They were never documented and would throw when called.

### DEP0114: crypto._toBuf()#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v11.0.0 | Runtime deprecation.

Type: End-of-Life

The `crypto._toBuf()` function was not designed to be used by modules outside of Node.js core and was removed.

### DEP0115: crypto.prng(), crypto.pseudoRandomBytes(), crypto.rng()#

History

Version | Changes
--- | ---
v11.0.0 | Added documentation-only deprecation with `--pending-deprecation` support.

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.

### DEP0116: Legacy URL API#

History

Version | Changes
--- | ---
v11.0.0 | Documentation-only deprecation.

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.

### DEP0117: Native crypto handles#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v11.0.0 | Runtime deprecation.

Type: End-of-Life

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. The `_handle` property has been removed because improper use of the native object can lead to crashing the application.

### DEP0118: dns.lookup() support for a falsy hostname[src]#

History

Version | Changes
--- | ---
v11.0.0 | Runtime deprecation.

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.

### DEP0119: process.binding('uv').errname() private API#

History

Version | Changes
--- | ---
v11.0.0 | Documentation-only deprecation.

Type: Documentation-only (supports `--pending-deprecation`)

`process.binding('uv').errname()` is deprecated. Please use `util.getSystemErrorName()` instead.

### DEP0120: Windows Performance Counter Support#

History

Version | Changes
--- | ---
v12.0.0 | End-of-Life.
v11.0.0 | Runtime deprecation.

Type: End-of-Life

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.

### DEP0121: net._setSimultaneousAccepts()#

History

Version | Changes
--- | ---
v12.0.0 | Runtime deprecation.

Type: Runtime

The undocumented `net._setSimultaneousAccepts()` function was originally intended for debugging and performance tuning when using the `child_process` and `cluster` modules on Windows. The function is not generally useful and is being removed. See discussion here: https://github.com/nodejs/node/issues/18391

### DEP0122: tls Server.prototype.setOptions()#

History

Version | Changes
--- | ---
v12.0.0 | Runtime deprecation.

Type: Runtime

Please use `Server.prototype.setSecureContext()` instead.

### DEP0123: setting the TLS ServerName to an IP address#

History

Version | Changes
--- | ---
v12.0.0 | Runtime deprecation.

Type: Runtime

Setting the TLS ServerName to an IP address is not permitted by RFC 6066. This will be ignored in a future version.

### DEP0124: using REPLServer.rli#

History

Version | Changes
--- | ---
v12.0.0 | Runtime deprecation.

Type: Runtime

This property is a reference to the instance itself.

### DEP0125: require('_stream_wrap')#

History

Version | Changes
--- | ---
v12.0.0 | Runtime deprecation.

Type: Runtime

The `_stream_wrap` module is deprecated.

### DEP0126: timers.active()#

History

Version | Changes
--- | ---
v11.14.0 | Runtime deprecation.

Type: Runtime

The previously undocumented `timers.active()` is deprecated. Please use the publicly documented `timeout.refresh()` instead. If re-referencing the timeout is necessary, `timeout.ref()` can be used with no performance impact since Node.js 10.

### DEP0127: timers._unrefActive()#

History

Version | Changes
--- | ---
v11.14.0 | Runtime deprecation.

Type: Runtime

The previously undocumented and "private" `timers._unrefActive()` is deprecated. Please use the publicly documented `timeout.refresh()` instead. If unreferencing the timeout is necessary, `timeout.unref()` can be used with no performance impact since Node.js 10.

### DEP0128: modules with an invalid `main` entry and an `index.js` file#

History

Version | Changes
--- | ---
v12.0.0 | Documentation-only.

Type: Documentation-only (supports `--pending-deprecation`)

Modules that have an invalid `main` entry (e.g., `./does-not-exist.js`) and also have an `index.js` file in the top level directory will resolve the `index.js` file. That is deprecated and is going to throw an error in future Node.js versions.

### DEP0129: ChildProcess._channel#

History

Version | Changes
--- | ---
v11.14.0 | Documentation-only.

Type: Documentation-only

The `_channel` property of child process objects returned by `spawn()` and similar functions is not intended for public use. Use `ChildProcess.channel` instead.

### DEP0130: Module.createRequireFromPath()#

History

Version | Changes
--- | ---
v12.2.0 | Documentation-only.

Type: Documentation-only

Module.createRequireFromPath() is deprecated. Please use `module.createRequire()` instead.

### DEP0131: Legacy HTTP parser#

History

Version | Changes
--- | ---
v12.3.0 | Documentation-only.

Type: Documentation-only

The legacy HTTP parser, used by default in versions of Node.js prior to 12.0.0, is deprecated. This deprecation applies to users of the `--http-parser=legacy` command-line flag.

### DEP0132: worker.terminate() with callback#

History

Version | Changes
--- | ---
v12.5.0 | Runtime deprecation.

Type: Runtime

Passing a callback to `worker.terminate()` is deprecated. Use the returned `Promise` instead, or a listener to the worker’s `'exit'` event.