⚡ sparkid

Fast, monotonic, time-sortable, 21-char Base58 unique ID generator. Zero dependencies.

1ocmpHE1bFnygEBAPTzMK
1ocmpHE1bFnygFv4Wp4dL
1ocmpHE1bFnygGoUXUL7X

Install

npm install sparkid

Usage

import { generateId } from "sparkid";

const id = generateId();
// => "1ocmpHE1bFnygEBAPTzMK"

Extract timestamp

import { extractTimestamp } from "sparkid";

const id = generateId();
const date = extractTimestamp(id);
console.log(date.toISOString());
// => "2025-11-14T22:13:20.000Z"

Binary representation

Pack IDs into 16 bytes for compact storage. Sort order is preserved — memcmp on the binary bytes gives the same ordering as string comparison.

import { toBytes, fromBytes } from "sparkid/binary";

const id = generateId();

const bytes = toBytes(id);    // Uint8Array(16)
const restored = fromBytes(bytes);
console.log(id === restored); // true

Properties

| Property | Value | |---|---| | Length | 21 characters, fixed | | Alphabet | Base58 (no 0, O, I, l) | | Sortable | Lexicographically, by creation time | | Monotonic | Strictly increasing within the process | | URL-safe | Yes | | Collision resistance | ~58^13 (~8.4 x 10^22) combinations per millisecond | | Randomness | Cryptographically secure (crypto.getRandomValues) |

How it works

Each ID is composed of two parts:

[8-char timestamp][13-char suffix]

• Timestamp (8 chars): Current time in milliseconds, Base58-encoded. IDs generated in a later millisecond always sort after earlier ones.
• Suffix (13 chars): Seeded from crypto.getRandomValues (rejection-sampled, no modulo bias) at the start of each millisecond, then monotonically incremented for each subsequent ID within that millisecond. This guarantees strict ordering even when multiple IDs share a timestamp.

Ordering guarantees

All IDs generated by generateId() within a single process are strictly monotonically increasing — every ID is lexicographically greater than the one before it. Since JavaScript is single-threaded, this means process-wide monotonicity with no additional coordination needed.

Platform support

Works in any environment with crypto.getRandomValues:

• Node.js >= 19
• All modern browsers
• Deno
• Bun
• Cloudflare Workers

License

MIT