Short UUID Generator

What is a Short UUID Generator

A UUID is fixed at 16 bytes, but its usual spelling is wasteful: 36 characters, four of which are hyphens and 32 of which use only 16 of the symbols a URL can carry. Re-encoding those same bytes in base64url produces 22 characters — a 39% saving with no loss at all, and the result survives being put in a query string, a filename or a cookie without escaping.

Entropy is the part you can choose. 8 bytes give 64 bits, 12 bytes give 96 and the full 16 bytes keep the 128 bits of a UUID. The birthday bound makes the trade-off concrete: with 64 bits, a collision becomes plausible after roughly a few hundred million values, while 96 bits stay safe for any realistic table and 128 bits are effectively beyond reach.

What you give up is structure. A compressed UUID has no version nibble and no variant bits, so it is no longer self-describing — a database cannot extract a timestamp from it, and a validator cannot say which version it is. If you need that metadata, use a real v4 or v7; if you only need a compact, opaque key, the short form is the better fit.

How to

1. Set how many identifiers you need.
2. Choose the bytes of randomness: 8 bytes for 11 characters, 12 for 16, or 16 for a 22-character compressed UUID.
3. Press Generate, then copy a single value or export the whole batch.

Use cases

• Short links and files where a 36-character name is awkward to read aloud or paste.
• Compact database keys when a 22-character text column is cheaper than a 36-character one.
• Cache keys and request ids, where the value only has to be unique, not parseable.

Compare Short UUID Generator with other formats

Code examples

JavaScript

// Node 18+ / modern browsers: 16 bytes -> 22 URL-safe characters
const bytes = crypto.getRandomValues(new Uint8Array(16));
const id = Buffer.from(bytes).toString('base64url');   // 22 chars

// Browser-only variant
const id2 = btoa(String.fromCharCode(...bytes))
  .replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '');

Python

import os, base64

# 16 bytes -> 22 characters (no padding), URL-safe
id_ = base64.urlsafe_b64encode(os.urandom(16)).rstrip(b'=').decode()

# 8 bytes -> 11 characters
short = base64.urlsafe_b64encode(os.urandom(8)).rstrip(b'=').decode()

# Decoding a compressed UUID back to canonical form
import uuid
raw = base64.urlsafe_b64decode(id_ + '==')
print(uuid.UUID(bytes=raw))

Frequently asked questions