sparkid

Fast, monotonic, time-sortable, 22-char Base58 unique ID generator. Zero dependencies.

1ocmpHE1bFnygEBAPTzMK4
1ocmpHE1bFnygFv4Wp4dL2
1ocmpHE1bFnygGoUXUL7Xo

Install

npm install sparkid

Usage

import { generateId } from "sparkid";

const id = generateId();
// => "1ocmpHE1bFnygEBAPTzMK4"

Properties

| Property | Value | |---|---| | Length | 22 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 | ~58^14 (~1.8 x 10^24) combinations per millisecond | | Randomness | Cryptographically secure (crypto.getRandomValues) |

How it works

Each ID is composed of two parts:

[8-char timestamp][14-char suffix]

• Timestamp (8 chars): Current time in milliseconds, Base58-encoded. IDs generated in a later millisecond always sort after earlier ones.
• Suffix (14 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.

Performance

~22 million IDs/sec on Node.js (~0.05 µs/call):

npm run bench

Platform support

Works in any environment with crypto.getRandomValues:

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

License

MIT