UUID Generator
UUID v4 / v7, ULID, Nano ID, hex token, short ID. Crypto-secure. Batch up to 1000.
published
- [FREE]
- [NO_SIGNUP]
- [NO_UPLOAD]
A UUID generator produces cryptographically-random or time-ordered IDs in the format you need: UUID v4 / v7, ULID, Nano ID, hex token, or short ID. All generated locally in your browser via crypto.getRandomValues.
Comparison
| Type | Length | Ordered | Chars |
|---|---|---|---|
| UUID v4 | 36 (with hyphens) | no | 0-9, a-f |
| UUID v7 | 36 | yes (time prefix) | 0-9, a-f |
| ULID | 26 | yes | 0-9, A-Z (Crockford b32) |
| Nano ID | 21 (configurable) | no | A-Z, a-z, 0-9, _, - |
| Hex token | 1-256 (configurable) | no | 0-9, a-f |
| Short ID | 8 | no | A-Z, a-z, 0-9, _, - |
When to pick each
- UUID v4: default for cross-system IDs. Universal support.
- UUID v7: database primary keys where insert order matters.
- ULID: like v7 but Crockford b32 (avoids 0/O and 1/I confusion).
- Nano ID: URL-safe shorter alternative to UUID.
- Hex token: API keys, password-reset tokens, cache buster strings.
- Short ID: display-only handles (8 chars random).
Privacy
A static HTML page with a tiny JS bundle. No upload, no analytics.
Related tools
- Hash Generator — SHA-256 of arbitrary content.
- Base64 Encoder — when you need URL-safe encoded bytes.
Frequently asked questions
Which ID type should I use?
UUID v4 is the modern default — 122 random bits, no ordering. UUID v7 adds a time prefix for index-friendly database keys without losing uniqueness. ULID is similar but uses Crockford base32 (case-insensitive, no ambiguous chars). Nano ID is shorter (21 chars) and URL-safe. Hex token is for API keys / one-time codes.
Is the randomness cryptographically secure?
Yes. All IDs are derived from crypto.getRandomValues (the browser-native CSPRNG). Same source used by WebCrypto.
Why time-ordered UUIDs?
Database B-tree indexes degrade when keys are inserted in random order (page splits, write amplification). UUID v7 / ULID prefix the timestamp so new keys append to the right side of the index — better insert performance, locality for time-range scans, and you can recover the creation time from the ID.
Privacy?
Pure JS + WebCrypto. Nothing leaves the browser.