.. | ||
async | ||
bin | ||
non-secure | ||
url-alphabet | ||
CHANGELOG.md | ||
index.browser.js | ||
index.cjs | ||
index.d.ts | ||
index.js | ||
LICENSE | ||
nanoid.js | ||
package.json | ||
README.md |
Nano ID
A tiny, secure, URL-friendly, unique string ID generator for JavaScript.
“An amazing level of senseless perfectionism, which is simply impossible not to respect.”
- Small. 108 bytes (minified and gzipped). No dependencies. Size Limit controls the size.
- Fast. It is 40% faster than UUID.
- Safe. It uses cryptographically strong random APIs. Can be used in clusters.
- Compact. It uses a larger alphabet than UUID (
A-Za-z0-9_-
). So ID size was reduced from 36 to 21 symbols. - Portable. Nano ID was ported to 14 programming languages.
import { nanoid } from 'nanoid'
model.id = nanoid() //=> "V1StGXR8_Z5jdHi6B-myT"
Supports modern browsers, IE with Babel, Node.js and React Native.
Table of Contents
Comparison with UUID
Nano ID is quite comparable to UUID v4 (random-based). It has a similar number of random bits in the ID (126 in Nano ID and 122 in UUID), so it has a similar collision probability:
For there to be a one in a billion chance of duplication, 103 trillion version 4 IDs must be generated.
There are three main differences between Nano ID and UUID v4:
- Nano ID uses a bigger alphabet, so a similar number of random bits are packed in just 21 symbols instead of 36.
- Nano ID code is 3 times less than
uuid/v4
package: 108 bytes instead of 345. - Because of memory allocation tricks, Nano ID is 16% faster than UUID.
Benchmark
$ ./test/benchmark
nanoid 655,798 ops/sec
customAlphabet 635,421 ops/sec
uid.sync 375,816 ops/sec
uuid v4 396,756 ops/sec
secure-random-string 366,434 ops/sec
cuid 183,998 ops/sec
shortid 59,343 ops/sec
Async:
async nanoid 101,966 ops/sec
async customAlphabet 102,471 ops/sec
async secure-random-string 97,206 ops/sec
uid 91,291 ops/sec
Non-secure:
non-secure nanoid 2,754,423 ops/sec
rndm 2,437,262 ops/sec
Test configuration: Dell XPS 2-in-a 7390, Fedora 32, Node.js 13.11.
Tools
- ID size calculator shows collision probability when adjusting the ID alphabet or size.
nanoid-dictionary
with popular alphabets to use withcustomAlphabet
.nanoid-good
to be sure that your ID doesn’t contain any obscene words.
Security
See a good article about random generators theory: Secure random values (in Node.js)
-
Unpredictability. Instead of using the unsafe
Math.random()
, Nano ID uses thecrypto
module in Node.js and the Web Crypto API in browsers. These modules use unpredictable hardware random generator. -
Uniformity.
random % alphabet
is a popular mistake to make when coding an ID generator. The distribution will not be even; there will be a lower chance for some symbols to appear compared to others. So, it will reduce the number of tries when brute-forcing. Nano ID uses a better algorithm and is tested for uniformity. -
Vulnerabilities: to report a security vulnerability, please use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.
Usage
JS
The main module uses URL-friendly symbols (A-Za-z0-9_-
) and returns an ID
with 21 characters (to have a collision probability similar to UUID v4).
import { nanoid } from 'nanoid'
model.id = nanoid() //=> "Uakgb_J5m9g-0JDMbcJqLJ"
If you want to reduce the ID size (and increase collisions probability), you can pass the size as an argument.
nanoid(10) //=> "IRFa-VaY2b"
Don’t forget to check the safety of your ID size in our ID collision probability calculator.
You can also use a custom alphabet or a random generator.
IE
If you support IE, you need to transpile node_modules
by Babel
and add crypto
alias:
// polyfills.js
if (!window.crypto) {
window.crypto = window.msCrypto
}
import './polyfills.js'
import { nanoid } from 'nanoid'
React
Do not call nanoid
in the key
prop. In React, key
should be consistent
among renders.
This is the bad example:
<Item key={nanoid()} /> /* DON’T DO IT */
This is the good example (id
will be generated only once):
const Element = () => {
const [id] = React.useState(nanoid)
return <Item key={id} />
}
If you want to use Nano ID in the id
prop, you must set some string prefix
(it is invalid for the HTML ID to start with a number).
<input id={'id' + this.id} type="text"/>
Create React App
Create React App has a problem with ES modules packages.
TypeError: (0 , _nanoid.nanoid) is not a function
If you have an error above, here is temporary fix:
- Use Nano ID 2 instead of 3:
npm i nanoid@^2.0.0
. - Vote for pull request, that fix dual packages support.
React Native
React Native does not have built-in random generator.
- Check
react-native-get-random-values
docs and install it. - Import it before Nano ID.
import 'react-native-get-random-values'
import { nanoid } from 'nanoid'
For Expo framework see the next section.
Expo
If you use Expo in React Native, you need a different workaround.
- Install
expo-random
. - Use
nanoid/async
instead ofnanoid
. - Import
index.native.js
file directly.
import { nanoid } from 'nanoid/async/index.native'
async function createUser () {
user.id = await nanoid()
}
PouchDB and CouchDB
In PouchDB and CouchDB, IDs can’t start with an underscore _
.
A prefix is required to prevent this issue, as Nano ID might use a _
at the start of the ID by default.
Override the default ID with the following option:
db.put({
_id: 'id' + nanoid(),
…
})
Mongoose
const mySchema = new Schema({
_id: {
type: String,
default: () => nanoid()
}
})
ES Modules
Nano ID provides ES modules. You do not need to do anything to use Nano ID as ESM in webpack, Rollup, Parcel, or Node.js.
import { nanoid } from 'nanoid'
For quick hacks, you can load Nano ID from CDN. Special minified
nanoid.js
module is available on jsDelivr.
Though, it is not recommended to be used in production because of the lower loading performance.
import { nanoid } from 'https://cdn.jsdelivr.net/npm/nanoid/nanoid.js'
Web Workers
Web Workers do not have access to a secure random generator.
Security is important in IDs when IDs should be unpredictable. For instance, in "access by URL" link generation. If you do not need unpredictable IDs, but you need to use Web Workers, you can use the non‑secure ID generator.
import { nanoid } from 'nanoid/non-secure'
nanoid() //=> "Uakgb_J5m9g-0JDMbcJqLJ"
Note: non-secure IDs are more prone to collision attacks.
CLI
You can get unique ID in terminal by calling npx nanoid
. You need only
Node.js in the system. You do not need Nano ID to be installed anywhere.
$ npx nanoid
npx: installed 1 in 0.63s
LZfXLFzPPR4NNrgjlWDxn
If you want to change alphabet or ID size, you should use nanoid-cli
.
Other Programming Languages
Nano ID was ported to many languages. You can use these ports to have the same ID generator on the client and server side.
- C#
- C++
- Clojure and ClojureScript
- Crystal
- Dart
- Deno
- Go
- Elixir
- Haskell
- Janet
- Java
- Nim
- PHP
- Python with dictionaries
- Ruby
- Rust
- Swift
Also, CLI is available to generate IDs from a command line.
API
Async
To generate hardware random bytes, CPU collects electromagnetic noise. In the synchronous API during the noise collection, the CPU is busy and cannot do anything useful in parallel.
Using the asynchronous API of Nano ID, another code can run during the entropy collection.
import { nanoid } from 'nanoid/async'
async function createUser () {
user.id = await nanoid()
}
Unfortunately, you will lose Web Crypto API advantages in a browser if you the asynchronous API. So, currently, in the browser, you are limited with either security or asynchronous behavior.
Non-Secure
By default, Nano ID uses hardware random bytes generation for security and low collision probability. If you are not so concerned with security and more concerned with performance, you can use the faster non-secure generator.
import { nanoid } from 'nanoid/non-secure'
const id = nanoid() //=> "Uakgb_J5m9g-0JDMbcJqLJ"
Note: your IDs will be more predictable and prone to collision attacks.
Custom Alphabet or Size
customAlphabet
allows you to create nanoid
with your own alphabet
and ID size.
import { customAlphabet } from 'nanoid'
const nanoid = customAlphabet('1234567890abcdef', 10)
model.id = nanoid() //=> "4f90d13a42"
Check the safety of your custom alphabet and ID size in our
ID collision probability calculator. For more alphabets, check out the options
in nanoid-dictionary
.
Alphabet must contain 256 symbols or less. Otherwise, the security of the internal generator algorithm is not guaranteed.
Customizable asynchronous and non-secure APIs are also available:
import { customAlphabet } from 'nanoid/async'
const nanoid = customAlphabet('1234567890abcdef', 10)
async function createUser () {
user.id = await nanoid()
}
import { customAlphabet } from 'nanoid/non-secure'
const nanoid = customAlphabet('1234567890abcdef', 10)
user.id = nanoid()
Custom Random Bytes Generator
customRandom
allows you to create a nanoid
and replace alphabet
and the default random bytes generator.
In this example, a seed-based generator is used:
import { customRandom } from 'nanoid'
const rng = seedrandom(seed)
const nanoid = customRandom('abcdef', 10, size => {
return (new Uint8Array(size)).map(() => 256 * rng())
})
nanoid() //=> "fbaefaadeb"
random
callback must accept the array size and return an array
with random numbers.
If you want to use the same URL-friendly symbols with customRandom
,
you can get the default alphabet using the urlAlphabet
.
const { customRandom, urlAlphabet } = require('nanoid')
const nanoid = customRandom(urlAlphabet, 10, random)
Asynchronous and non-secure APIs are not available for customRandom
.