shortid vs nanoid vs randomstring vs uuid
Generating Unique Identifiers in JavaScript Applications
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Generating Unique Identifiers in JavaScript Applications

nanoid, randomstring, shortid, and uuid are all npm packages used to generate unique identifiers in JavaScript applications, but they differ significantly in design goals, collision resistance, output format, and suitability for modern frontend environments. uuid is the most mature and standards-compliant, producing universally unique identifiers (UUIDs) per RFC specifications. nanoid focuses on compact, URL-safe IDs with minimal size and high performance using cryptographically strong randomness. randomstring offers flexible string generation with extensive customization options but isn’t specifically designed for unique ID use cases. shortid was created to produce short, non-sequential IDs but has known limitations in uniqueness guarantees and is no longer maintained.

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shortid990,0705,71421.7 kB16a year agoMIT
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Generating Unique IDs in JavaScript: nanoid vs randomstring vs shortid vs uuid

When building modern web apps, you’ll often need to generate unique identifiers — for temporary DOM elements, client-side entity keys, cache entries, or sync tokens. But not all ID generators are created equal. Let’s break down how nanoid, randomstring, shortid, and uuid actually behave in real-world frontend scenarios.

🔢 What Kind of ID Do You Really Need?

Before comparing libraries, ask: What problem am I solving?

  • Globally unique across systems? → Use uuid.
  • Short, fast, client-only IDs? → Use nanoid.
  • Custom-formatted random text (not necessarily unique)? → Consider randomstring.
  • Legacy compatibility? → Avoid shortid; migrate away.

Each package makes different trade-offs between size, safety, standardization, and flexibility.

🧪 Collision Resistance: How Safe Is "Unique"?

uuid generates RFC-compliant identifiers. Version 4 (random-based) uses 122 bits of entropy — so the chance of collision is astronomically low, even at billions of IDs per second. This is why databases like PostgreSQL natively support UUIDs.

// uuid v4 example
import { v4 as uuidv4 } from 'uuid';
const id = uuidv4(); // '9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d'

nanoid uses a larger alphabet (A-Za-z0-9_-) and defaults to 21 characters, giving ~126 bits of entropy — comparable to UUID v4 but in a shorter string. It leverages the browser’s crypto.getRandomValues() for true randomness, making it safe for client-side use.

// nanoid example
import { nanoid } from 'nanoid';
const id = nanoid(); // 'V1StGXR8_Z5jdHi6B-myT'

randomstring doesn’t guarantee uniqueness. It’s a general-purpose string generator. If you call it twice with the same settings, you might get duplicates — and there’s no built-in mechanism to prevent that.

// randomstring — not for unique IDs!
import randomstring from 'randomstring';
const str = randomstring.generate(10); // 'aB3xK9mQ2p' — could repeat

shortid uses only 7–14 characters with a small alphabet, resulting in very limited entropy. Worse, it relied on a shared internal counter that resets on app restart — causing predictable sequences and high collision risk in serverless or multi-tab environments. It is deprecated and should not be used in new code.

📏 Output Format and Size Matter

  • uuid: Always 36 chars (with hyphens). Hard to shorten safely.
  • nanoid: Default 21 chars, no special characters, URL-safe.
  • randomstring: Fully configurable — but defaults aren’t optimized for IDs.
  • shortid: ~7–10 chars, but unsafe.

If you’re embedding IDs in URLs or class names, nanoid’s compact, clean output wins. For database keys or API payloads where standards matter, uuid’s structure is an advantage.

🌐 Browser Compatibility and Security

All four work in browsers, but security differs:

  • nanoid and uuid both use cryptographically secure random sources in modern browsers (crypto.getRandomValues).
  • randomstring falls back to Math.random() unless you explicitly enable secure mode — which many developers forget.
  • shortid used insecure randomness in early versions and never updated its approach.

Never trust Math.random() for anything requiring uniqueness or unpredictability — it’s deterministic and easily guessable.

⚙️ Customization vs Simplicity

Need a 12-character alphanumeric ID without vowels (to avoid accidental words)? randomstring can do that:

randomstring.generate({
  length: 12,
  charset: 'abcdefghjkmnpqrstuvwxyz23456789'
});

But if you just need a safe, short ID with zero config, nanoid is simpler:

nanoid(12); // 'K7cL9pXqR2mN'

uuid offers versioned generation (e.g., time-based v1 or lexicographically sortable v7), useful for databases, but adds complexity if you don’t need it.

🛑 The Shortid Situation

shortid was popular around 2016–2018 for its brevity, but its author officially deprecated it in 2019, recommending nanoid as a replacement. Known issues include:

  • Collisions after ~16k IDs in a single process
  • Non-cryptographic randomness
  • No updates for modern JavaScript environments

If you see it in a codebase, treat it as technical debt.

✅ Practical Recommendations

Use CaseBest Choice
Client-side React keys, temp IDsnanoid
Database primary keys, API identifiersuuid (v4 or v7)
Test data, passwords, mock contentrandomstring
Any new project needing short IDsNot shortid — use nanoid

💡 Pro Tip: Avoid Reinventing the Wheel

Don’t roll your own ID generator using Date.now() + Math.random(). Even subtle bugs can cause hard-to-debug duplication issues in production. Stick to battle-tested libraries that understand entropy, randomness, and collision math.

In summary: Use nanoid for short client IDs, uuid for system-wide uniqueness, randomstring for non-unique random text, and never shortid in new code.

How to Choose: shortid vs nanoid vs randomstring vs uuid

  • shortid:

    Do not choose shortid for new projects. It is deprecated and no longer maintained, with documented issues around ID collisions under moderate load due to its limited entropy and reliance on process-specific counters. If you’re maintaining legacy code that uses it, plan a migration to nanoid or uuid.

  • nanoid:

    Choose nanoid when you need very short, URL-safe identifiers with strong uniqueness guarantees and minimal bundle impact. It’s ideal for client-side ID generation in SPAs, cache keys, or temporary DOM element IDs where size and speed matter. Its use of cryptographic randomness (via Web Crypto API in browsers) ensures low collision risk even at scale, and it avoids problematic characters like hyphens or underscores by default.

  • randomstring:

    Choose randomstring when your primary need is customizable random strings — not necessarily globally unique IDs. It shines in scenarios like password generation, test fixtures, or placeholder content where you control length, character sets, and patterns. However, avoid it for distributed ID generation since it lacks built-in collision resistance strategies and isn’t optimized for uniqueness.

  • uuid:

    Choose uuid when you need standards-compliant, universally unique identifiers — especially if interoperability with backend systems, databases, or external APIs is required. It supports multiple UUID versions (v1, v4, v7), with v4 being the most common for random IDs. While slightly larger than nanoid outputs (36 characters vs ~21), its predictability, widespread adoption, and robust collision resistance make it the safe default for most production systems.

Similar Npm Packages to shortid

shortid is a small, simple, and efficient library for generating unique IDs in JavaScript applications. It is particularly useful when you need to create unique identifiers for objects, database entries, or any other purpose where uniqueness is essential. While shortid is a popular choice for generating unique IDs, there are several alternatives available that offer similar functionality. Here are a few notable alternatives:

  • nanoid is a tiny, secure, and URL-friendly unique string ID generator. It is designed to be faster and more efficient than traditional ID generators. With a customizable length and a focus on security, nanoid is a great choice for applications that require unique IDs that are both compact and collision-resistant. Its performance and security features make it suitable for a wide range of applications, from web development to server-side programming.
  • uniqid is another library for generating unique IDs, focusing on simplicity and ease of use. It generates unique IDs based on the current timestamp and a random number, ensuring that the IDs are unique across different instances. uniqid is a great option if you need a straightforward solution for generating unique identifiers without any additional complexity.
  • uuid is a widely used library for generating universally unique identifiers (UUIDs). It follows the RFC4122 standard and provides several versions of UUIDs, including random and time-based variants. uuid is an excellent choice for applications that require a standardized format for unique identifiers, especially in distributed systems or databases where uniqueness across different machines is crucial.

To see how shortid compares with nanoid, uniqid, and uuid, check out the comparison: Comparing nanoid vs shortid vs uniqid vs uuid.

Similar Npm Packages to nanoid

nanoid is a tiny, secure, URL-friendly, unique string ID generator for JavaScript. It is designed to be fast and efficient, producing unique IDs that are shorter than traditional UUIDs while still being highly collision-resistant. This makes nanoid an excellent choice for applications that require unique identifiers, such as database keys, session tokens, or any other scenario where unique strings are needed. Its lightweight nature and performance make it a popular choice among developers.

However, there are several alternatives to nanoid that also provide unique ID generation capabilities. Here are a few notable ones:

  • shortid is a simple, fast, and non-cryptographic unique ID generator. It generates short, unique, and URL-friendly IDs based on the current timestamp, machine ID, and random numbers. While it is easy to use and produces shorter IDs than UUIDs, it is less collision-resistant than nanoid, making it more suitable for scenarios where absolute uniqueness is not critical.
  • uniqid is another unique ID generator that produces unique IDs based on the current timestamp and a random number. It is designed to be simple and efficient, generating unique strings that are also relatively short. While uniqid is straightforward to use, it may not provide the same level of collision resistance as nanoid, especially in high-concurrency situations.
  • uuid is a widely used library for generating universally unique identifiers (UUIDs). It adheres to the RFC4122 standard and provides various methods for generating different versions of UUIDs. While UUIDs are longer and more complex than the IDs generated by nanoid, they are highly reliable for ensuring uniqueness across distributed systems. If your application requires strict adherence to UUID standards, using the uuid library is a solid choice.

To see how nanoid compares with shortid, uniqid, and uuid, check out the comparison: Comparing nanoid vs shortid vs uniqid vs uuid.

Similar Npm Packages to randomstring

randomstring is a simple and efficient npm package for generating random strings in JavaScript. It allows developers to create strings of various lengths and character sets, making it useful for generating unique identifiers, passwords, or any other random strings needed in an application. While randomstring is a reliable choice for generating random strings, there are several alternatives available that cater to different use cases. Here are a few notable options:

  • nanoid is a tiny, secure, and fast unique string ID generator. It is designed to create unique IDs with a customizable length and character set, making it an excellent choice for generating unique identifiers for database entries, session tokens, or any other purpose where uniqueness is crucial. nanoid is particularly favored for its performance and security features, making it a popular choice for modern web applications.
  • shortid is another library for generating short, unique, non-sequential IDs. It is designed to create compact IDs that can be used in various scenarios, such as database keys or URL slugs. shortid is easy to use and provides a straightforward API, but it is worth noting that it is not as actively maintained as some of the other options. If you need a simple solution for generating short unique IDs, shortid can still be a viable choice.
  • uuid is a widely-used library for generating universally unique identifiers (UUIDs). It follows the RFC4122 standard and provides various methods for generating different versions of UUIDs. uuid is particularly useful when you need a standard format for unique identifiers, such as when interacting with databases or APIs that expect UUIDs. Its robustness and adherence to standards make it a go-to solution for many developers.

To see how randomstring compares with nanoid, shortid, and uuid, check out the comparison: Comparing nanoid vs randomstring vs shortid vs uuid.

Similar Npm Packages to uuid

uuid is a popular npm package used for generating universally unique identifiers (UUIDs). UUIDs are 128-bit numbers used to uniquely identify information in computer systems. The uuid package provides various methods for generating UUIDs according to different versions of the UUID standard, making it a versatile choice for developers needing unique identifiers in their applications. While uuid is widely used, there are several alternatives available that also serve the purpose of generating unique identifiers. Here are a few notable alternatives:

  • node-uuid was one of the original libraries for generating UUIDs in Node.js applications. It provided a simple interface for generating UUIDs but has since been deprecated in favor of the uuid package. While it still exists, developers are encouraged to use the uuid package for better support and updated features.
  • shortid is a library that generates short, unique, non-sequential ids. Unlike UUIDs, which are long and standardized, shortid produces shorter identifiers that are easier to read and use in URLs or as keys in databases. If your application requires unique identifiers that are compact and human-readable, shortid is a great alternative to consider.
  • uuidv4 is a specific implementation of UUID version 4, which generates random UUIDs. While uuidv4 is a simpler and more focused package compared to uuid, it is suitable for scenarios where you only need to generate version 4 UUIDs without the additional features provided by the uuid package. If your use case is straightforward and you only need random UUIDs, uuidv4 can be a lightweight option.

To explore how these packages compare, check out the comparison: Comparing node-uuid vs shortid vs uuid vs uuidv4.

README for shortid

shortid Build Status shortid

Amazingly short non-sequential url-friendly unique id generator.

shortid is deprecated, because the architecture is unsafe. we instead recommend Nano ID, which has the advantage of also being significantly faster than shortid

ShortId creates amazingly short non-sequential url-friendly unique ids. Perfect for url shorteners, MongoDB and Redis ids, and any other id users might see.

  • By default 7-14 url-friendly characters: A-Z, a-z, 0-9, _-
  • Supports cluster (automatically), custom seeds, custom alphabet.
  • Can generate any number of ids without duplicates, even millions per day.
  • Perfect for games, especially if you are concerned about cheating so you don't want an easily guessable id.
  • Apps can be restarted any number of times without any chance of repeating an id.
  • Popular replacement for Mongo ID/Mongoose ID.
  • Works in Node, io.js, and web browsers.
  • Includes Mocha tests.

ShortId does not generate cryptographically secure ids, so don't rely on it to make IDs which are impossible to guess.

Usage

const shortid = require('shortid');

console.log(shortid.generate());
// PPBqWA9

Mongoose Unique Id

_id: {
  'type': String,
  'default': shortid.generate
},

Browser Compatibility

The best way to use shortid in the browser is via browserify or webpack.

These tools will automatically only include the files necessary for browser compatibility.

All tests will run in the browser as well:

## build the bundle, then open Mocha in a browser to see the tests run.
$ grunt build open

Example

~/projects/shortid ❯ node examples/examples.js
eWRhpRV
23TplPdS
46Juzcyx
dBvJIh-H
2WEKaVNO
7oet_d9Z
dogPzIz8
nYrnfYEv
a4vhAoFG
hwX6aOr7

Real World Examples

shortId was created for Node Knockout 2011 winner for Most Fun Doodle Or Die. Millions of doodles have been saved with shortId filenames. Every log message gets a shortId to make it easy for us to look up later.

Here are some other projects that use shortId:

  • bevy - A simple server to manage multiple Node services.
  • capre - Cross-Server Data Replication.
  • cordova-build - an alternative to phonegap build that runs on your servers/agents.
  • couchdb-tools - A library of handy functions for use when working with CouchDB documents.
  • CleverStack/clever-email - E-mail system for CleverStack.
  • CloudTypes - JavaScript end2end implementation of the Cloud Types model for Eventual Consistency programming.
  • dnode-tarantula - an asynchronous rpc and event system for node.js based on dnode-protocol and TCP sockets.
  • mongoose-url-shortener - A simple URL Shortening library for NodeJS using Promises/A+ results.
  • mozilla/smokejumper - The Smoke Jumper project is an effort to bring dead simple, secure, P2P file sharing to Firefox.
  • shortness - Node based URL shortener that uses SQLite.
  • file-db - Document database that uses directories and files to store its data, supporting nested key-value objects in named collections.
  • resume-generator - Resume Generator.
  • riffmint - Collaboration in musical space.
  • rap1ds/dippa - Dippa Editor – A web-based LaTeX editor

API

var shortid = require('shortid');

shortid.generate()

Returns string non-sequential unique id.

Example

users.insert({
  _id: shortid.generate(),
  name: '...',
  email: '...'
});

shortid.characters(string)

Default: '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_'

Returns new alphabet as a string

Recommendation: If you don't like _ or -, you can to set new characters to use.

Optional

Change the characters used.

You must provide a string of all 64 unique characters. Order is not important.

The default characters provided were selected because they are url safe.

Example

// use $ and @ instead of - and _
shortid.characters('0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$@');

// any 64 unicode characters work, but I wouldn't recommend this.
shortid.characters('ⒶⒷⒸⒹⒺⒻⒼⒽⒾⒿⓀⓁⓂⓃⓄⓅⓆⓇⓈⓉⓊⓋⓌⓍⓎⓏⓐⓑⓒⓓⓔⓕⓖⓗⓘⓙⓚⓛⓜⓝⓞⓟⓠⓡⓢⓣⓤⓥⓦⓧⓨⓩ①②③④⑤⑥⑦⑧⑨⑩⑪⑫');

shortid.isValid(id)

Returns boolean

Check to see if an id is a valid shortid. Note: This only means the id could have been generated by shortid, it doesn't guarantee it.

Example

shortid.isValid('41XTDbE');
// true

shortid.isValid('i have spaces');
// false

shortid.worker(integer)

Default: process.env.NODE_UNIQUE_ID || 0

Recommendation: You typically won't want to change this.

Optional

If you are running multiple server processes then you should make sure every one has a unique worker id. Should be an integer between 0 and 16. If you do not do this there is very little chance of two servers generating the same id, but it is theoretically possible if both are generated in the exact same second and are generating the same number of ids that second and a half-dozen random numbers are all exactly the same.

Example

shortid.worker(1);

shortid.seed(integer)

Default: 1

Recommendation: You typically won't want to change this.

Optional

Choose a unique value that will seed the random number generator so users won't be able to figure out the pattern of the unique ids. Call it just once in your application before using shortId and always use the same value in your application.

Most developers won't need to use this, it's mainly for testing ShortId.

If you are worried about users somehow decrypting the id then use it as a secret value for increased encryption.

Example

shortid.seed(1000);

About the Author

Hi! Thanks for checking out this project! My name is Dylan Greene. When not overwhelmed with my two young kids I enjoy contributing to the open source community. I'm also a tech lead at Opower. @dylang @dylang

Here's some of my other Node projects:

NameDescriptionnpm Downloads
npm‑checkCheck for outdated, incorrect, and unused dependencies.npm-check
grunt‑notifyAutomatic desktop notifications for Grunt errors and warnings. Supports OS X, Windows, Linux.grunt-notify
space‑hogsDiscover surprisingly large directories from the command line.space-hogs
rssRSS feed generator. Add RSS feeds to any project. Supports enclosures and GeoRSS.rss
grunt‑promptInteractive prompt for your Grunt config using console checkboxes, text input with filtering, password fields.grunt-prompt
xmlFast and simple xml generator. Supports attributes, CDATA, etc. Includes tests and examples.xml
changelogCommand line tool (and Node module) that generates a changelog in color output, markdown, or json for modules in npmjs.org's registry as well as any public github.com repo.changelog
grunt‑attentionDisplay attention-grabbing messages in the terminalgrunt-attention
observatoryBeautiful UI for showing tasks running on the command line.observatory
anthologyModule information and stats for any @npmjs useranthology
grunt‑catEcho a file to the terminal. Works with text, figlets, ascii art, and full-color ansi.grunt-cat

This list was generated using anthology.

License

Copyright (c) 2016 Dylan Greene, contributors.

Released under the MIT license.

Screenshots are CC BY-SA (Attribution-ShareAlike).

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