Free UUID Generator Online — v4 & v7 in One Click
Need a UUID? Skip the terminal. Our free UUID generator creates UUID v4 and v7 identifiers instantly — no signup, no installation, runs 100% in your browser.
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UUID v4, v7, bulk generation up to 1000. Copy or download. Zero signup.
Open UUID Generator →What is a UUID?
A UUID (Universally Unique Identifier) — also called a GUID (Globally Unique Identifier) — is a 128-bit identifier that's virtually guaranteed to be unique. They look like this:
550e8400-e29b-41d4-a716-446655440000UUIDs are the standard for generating unique IDs in distributed systems, databases, APIs, and pretty much any software that needs unique identifiers without a central authority.
UUID v4 vs UUID v7: Which Should You Use?
| Feature | UUID v4 | UUID v7 |
|---|---|---|
| Generation method | Random (122 random bits) | Time-ordered (48-bit timestamp + 62 random bits) |
| Sortable? | ❌ No — random order | ✅ Yes — chronologically sortable |
| Database performance | ⚠️ Causes index fragmentation | ✅ Sequential inserts, better B-tree performance |
| Privacy | ✅ No timestamp leakage | ⚠️ Reveals creation time |
| Best for | General purpose, API keys, tokens | Database primary keys, event IDs, logs |
| RFC status | RFC 4122 (2005) | RFC 9562 (2024) |
When to Use UUID v4
- You need random, unpredictable identifiers (API keys, tokens)
- You don't need time-based sorting
- Privacy matters — v4 reveals nothing about when it was created
- Maximum compatibility — every language and database supports v4
When to Use UUID v7
- Database primary keys (huge performance win over v4)
- Event IDs or log entries that benefit from chronological ordering
- Distributed systems where you want roughly time-ordered IDs
- Any case where you'd consider a ULID or Snowflake ID
How to Generate UUIDs in Code
JavaScript / Node.js
// Built-in (Node.js 14.17+ / modern browsers)
crypto.randomUUID(); // UUID v4
// npm package for v7
import { v7 } from 'uuid';
v7(); // UUID v7 (time-ordered)Python
import uuid
str(uuid.uuid4()) # UUID v4
# For v7, use uuid6 package
from uuid6 import uuid7
str(uuid7())Or Just Use Our Tool
Our UUID generator handles all of this for you — pick v4 or v7, choose your format, generate up to 1000 at once, and copy or download the results.
Common UUID Formats
Lowercase: 550e8400-e29b-41d4-a716-446655440000
Uppercase: 550E8400-E29B-41D4-A716-446655440000
No hyphens: 550e8400e29b41d4a716446655440000
Braces: {550e8400-e29b-41d4-a716-446655440000}
URN: urn:uuid:550e8400-e29b-41d4-a716-446655440000Our generator supports all five formats. Pick whichever your database or API expects.
UUID Collision Probability
UUID v4 has 122 random bits, giving 5.3 × 10³⁶ possible values. To have a 50% chance of a collision, you'd need to generate approximately 2.7 × 10¹⁸ UUIDs — that's 2.7 quintillion. If you generated 1 billion UUIDs per second, it would take about 85 years to reach a 50% collision probability.
In practice: UUID collisions don't happen. You can safely use them as primary keys without worrying.
Why Our UUID Generator?
- Both v4 and v7 — most generators only offer v4
- Bulk generation — up to 1000 UUIDs at once
- 5 output formats — lowercase, uppercase, no hyphens, braces, URN
- 100% client-side — your UUIDs never leave your browser
- Copy or download — one click to copy, or download as .txt
- Zero signup — no accounts, no paywalls, no ads
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