Simple, fast generation of RFC4122 UUIDS.
Features:
Install it in your browser:
<script src="uuid.js"></script>
Or in node.js:
npm install uuid
var uuid = require('uuid');
// Generate a v1 (time-based) id
uuid.v1(); // -> '6c84fb90-12c4-11e1-840d-7b25c5ee775a'
// Generate a v4 (random) id
uuid.v4(); // -> '110ec58a-a0f2-4ac4-8393-c866d813b8d1'
options
[, buffer
[, offset
]]])Generate and return a RFC4122 v1 (timestamp-based) UUID.
options
- (Object) Optional uuid state to apply. Properties may include:
node
- (Array) Node id as Array of 6 bytes (per 4.1.6). Default: Randomly generated ID. See note 1.clockseq
- (Number between 0 - 0x3fff) RFC clock sequence. Default: An internally maintained clockseq is used.msecs
- (Number | Date) Time in milliseconds since unix Epoch. Default: The current time is used.nsecs
- (Number between 0-9999) additional time, in 100-nanosecond units. Ignored if msecs
is unspecified. Default: internal uuid counter is used, as per 4.2.1.2.buffer
- (Array | Buffer) Array or buffer where UUID bytes are to be written.
offset
- (Number) Starting index in buffer
at which to begin writing.
Returns buffer
, if specified, otherwise the string form of the UUID
Notes:
Example: Generate string UUID with fully-specified options
uuid.v1({
node: [0x01, 0x23, 0x45, 0x67, 0x89, 0xab],
clockseq: 0x1234,
msecs: new Date('2011-11-01').getTime(),
nsecs: 5678
}); // -> "710b962e-041c-11e1-9234-0123456789ab"
Example: In-place generation of two binary IDs
// Generate two ids in an array
var arr = new Array(32); // -> []
uuid.v1(null, arr, 0); // -> [02 a2 ce 90 14 32 11 e1 85 58 0b 48 8e 4f c1 15]
uuid.v1(null, arr, 16); // -> [02 a2 ce 90 14 32 11 e1 85 58 0b 48 8e 4f c1 15 02 a3 1c b0 14 32 11 e1 85 58 0b 48 8e 4f c1 15]
// Optionally use uuid.unparse() to get stringify the ids
uuid.unparse(buffer); // -> '02a2ce90-1432-11e1-8558-0b488e4fc115'
uuid.unparse(buffer, 16) // -> '02a31cb0-1432-11e1-8558-0b488e4fc115'
options
[, buffer
[, offset
]]])Generate and return a RFC4122 v4 UUID.
options
- (Object) Optional uuid state to apply. Properties may include:
random
- (Number[16]) Array of 16 numbers (0-255) to use in place of randomly generated valuesrng
- (Function) Random # generator to use. Set to one of the built-in generators - uuid.mathRNG
(all platforms), uuid.nodeRNG
(node.js only), uuid.whatwgRNG
(WebKit only) - or a custom function that returns an array[16] of byte values.buffer
- (Array | Buffer) Array or buffer where UUID bytes are to be written.
offset
- (Number) Starting index in buffer
at which to begin writing.
Returns buffer
, if specified, otherwise the string form of the UUID
Example: Generate string UUID with fully-specified options
uuid.v4({
random: [
0x10, 0x91, 0x56, 0xbe, 0xc4, 0xfb, 0xc1, 0xea,
0x71, 0xb4, 0xef, 0xe1, 0x67, 0x1c, 0x58, 0x36
]
});
// -> "109156be-c4fb-41ea-b1b4-efe1671c5836"
Example: Generate two IDs in a single buffer
var buffer = new Array(32); // (or 'new Buffer' in node.js)
uuid.v4(null, buffer, 0);
uuid.v4(null, buffer, 16);
Parse and unparse UUIDs
id
- (String) UUID(-like) stringbuffer
- (Array | Buffer) Array or buffer where UUID bytes are to be written. Default: A new Array or Buffer is usedoffset
- (Number) Starting index in buffer
at which to begin writing. Default: 0Example parsing and unparsing a UUID string
var bytes = uuid.parse('797ff043-11eb-11e1-80d6-510998755d10'); // -> <Buffer 79 7f f0 43 11 eb 11 e1 80 d6 51 09 98 75 5d 10>
var string = uuid.unparse(bytes); // -> '797ff043-11eb-11e1-80d6-510998755d10'
(Browsers only) Set uuid
property back to it's previous value.
Returns the uuid object.
Example:
var myUuid = uuid.noConflict();
myUuid.v1(); // -> '6c84fb90-12c4-11e1-840d-7b25c5ee775a'
Support for the following v1.2 APIs is available in v1.3, but is deprecated and will be removed in the next major version.
uuid() has become uuid.v4(), and the format
argument is now implicit in the buffer
argument. (i.e. if you specify a buffer, the format is assumed to be binary).
The class of container created when generating binary uuid data if no buffer argument is specified. This is expected to go away, with no replacement API.
In node.js
> cd test
> node test.js
In Browser
open test/test.html
Requires node.js
cd benchmark/
npm install
node benchmark.js
For a more complete discussion of uuid performance, please see the benchmark/README.md
file, and the benchmark wiki
For browser performance checkout the JSPerf tests.