unique-string-modern

Generate a cryptographically strong, URL-safe unique string that is shorter and faster than UUID. Zero dependencies, tiny output, ESM + CJS builds.

Install

npm i unique-string-modern

Usage

import uniqueString, { uniqueStringAsync } from "unique-string-modern";

const id = uniqueString();
// => e.g. "QvW4Vb2Q2A1G2xgPSa7yhw"

const shortId = uniqueString(12);
// => 12 chars, URL-safe

const asyncId = await uniqueStringAsync();

Why URL-safe?

The output uses Base64 URL encoding (characters A–Z, a–z, 0–9, -, _) and removes padding. This makes IDs safe for use in URLs, file names, and HTML attributes without escaping.

API

• uniqueString(length?: number): string – synchronous generator. Default length 22.
• uniqueStringAsync(length?: number): Promise<string> – async variant.

Both functions use the Web Crypto API (globalThis.crypto.getRandomValues) with a Node fallback.

Benchmark

Quick micro-benchmark (Node):

import { performance } from "node:perf_hooks";
import uniqueString from "unique-string-modern";
import { v4 as uuidv4 } from "uuid"; // optional

const N = 100_000;

let t = performance.now();
for (let i = 0; i < N; i++) uniqueString();
console.log("unique-string-modern:", Math.round(performance.now() - t), "ms");

t = performance.now();
for (let i = 0; i < N; i++) uuidv4();
console.log("uuid v4:", Math.round(performance.now() - t), "ms");

Expect unique-string-modern to be faster and output 22 characters vs UUID's 36.

Build & Test

npm run build
npm test

Size

The minified output is under 1KB.