UUID Generator
Generate Unique IDs Instantly.
UUID v1, v4, v6, v7 - ULID, NanoID, GUID and more. All generated client-side with cryptographic entropy. No tracking, no network calls.
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Infrastructure Utilities
A complete suite of developer utilities. Zero tracking, no external API calls, built for production.
ID Tools
UUID Generator
Generate standard RFC 4122 / RFC 9562 Universally Unique Identifiers. Supports v1, v4, v6 and v7 in one place.
UUID v4
Cryptographically random 128-bit identifier. The most widely used UUID version - zero predictability.
UUID v6
Reordered timestamp UUID. Monotonically sortable and fully backward-compatible with v1.
UUID v7
Unix-timestamp-ordered UUID. Ideal for database primary keys - better B-tree performance than v4.
NanoID
Compact, URL-safe unique ID. Smaller than UUID, customisable alphabet and length.
GUID Generator
Microsoft-style Globally Unique Identifier. Structurally identical to UUID v4, formatted for Windows ecosystems.
ULID Generator
Universally Unique Lexicographically Sortable Identifier. 128-bit, Crockford Base32 encoded, monotonically sortable.
UUID v1
Timestamp + MAC address based UUID. Partially sortable, useful for time-ordered distributed logs.
Security Tools
Built for Distributed Systems
UUIDs eliminate coordination overhead in distributed architectures. Generate identifiers anywhere, at any scale, without a central authority.
Cryptographic Entropy
UUID v4 uses crypto.getRandomValues() - the same CSPRNG used in TLS. Collision probability is astronomically low.
Zero Latency Generation
Everything runs in your browser. No round-trips, no API keys, no rate limits. Generate millions of IDs without touching a server.
Database Friendly
UUID v7 is time-ordered, making it ideal for indexed database primary keys. Better B-tree performance than random v4 at scale.
Globally Unique
Unlike auto-increment integers, UUIDs are unique across every machine, every datacenter, every timezone - no coordination required.
RFC Compliant
All generators strictly follow RFC 4122 (v1, v4) and RFC 9562 (v6, v7). Drop-in compatible with any UUID-aware library or database.
25+ Language Snippets
Copy-ready implementation code for JavaScript, Python, Go, Rust, Java, PHP, and 20+ more languages in the Developer Lab.
Pick the Right Format
| Format | Bits | Sortable | DB Friendly | Standard | Action |
|---|---|---|---|---|---|
| UUID v4 | 128 | ✗ | ✓ | RFC 4122 | Generate |
| UUID v7 | 128 | ✓ | ✓✓ | RFC 9562 | Generate |
| UUID v6 | 128 | ✓ | ✓ | RFC 9562 | Generate |
| UUID v1 | 128 | ~ | ✓ | RFC 4122 | Generate |
| ULID | 128 | ✓ | ✓✓ | Unofficial | Generate |
| NanoID | 126 | ✗ | ✓ | Unofficial | Generate |
| GUID | 128 | ✗ | ✓ | Microsoft | Generate |
What Is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit label standardized in RFC 4122 and RFC 9562. It is displayed as 32 hexadecimal digits in five groups - for example, 550e8400-e29b-41d4-a716-446655440000. UUIDs can be generated independently on any machine without a central authority, making them ideal for distributed systems, database primary keys, and API resource IDs.
UUID v4 uses cryptographic randomness and is the default choice for opaque identifiers. UUID v7 embeds a Unix millisecond timestamp, so new IDs sort chronologically - better for large database indexes than random v4. Our free UUID generator runs entirely in your browser: no sign-up, no server calls, and no tracking.
Frequently Asked Questions
What is a UUID?
A UUID is a 128-bit universally unique identifier defined by RFC 4122 and RFC 9562. It is represented as 36 characters in the format xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx, where M is the version and N is the variant. UUIDs are designed so that any machine can generate them without coordination.
What is the difference between UUID v4 and v7?
UUID v4 is fully random (122 bits of entropy) and ideal for opaque IDs like user sessions or API keys. UUID v7 combines a 48-bit Unix timestamp with random bits, producing time-ordered IDs that insert efficiently at the end of B-tree indexes - the recommended choice for database primary keys at scale.
Is this UUID generator free?
Yes. The UUID generator is completely free with no sign-up, no usage limits, and no API key required. Generate as many UUIDs as you need directly in your browser.
Are UUIDs generated on your servers?
No. All UUIDs are generated entirely in your browser using client-side JavaScript. Nothing is transmitted to our servers, logged, or stored. Your identifiers never leave your device.
What is the difference between UUID and GUID?
GUID (Globally Unique Identifier) is Microsoft's name for UUID. They are structurally identical and interchangeable in any RFC 4122-compliant system. GUIDs are often displayed in uppercase with curly braces in Windows and .NET contexts.
Which UUID version should I use for database primary keys?
For tables under ~10 million rows, UUID v4 works well. For larger tables or high-insert workloads, use UUID v7 or ULID - both are time-ordered and reduce B-tree index fragmentation compared to random v4.
Is UUID v4 truly random?
Yes. UUID v4 uses 122 bits of cryptographic randomness from your browser's CSPRNG (crypto.getRandomValues), making collisions astronomically unlikely - approximately 1 in 5.3 × 10³⁶.
Use It Locally
Copy-ready snippets for your stack. Zero dependencies for most languages - just native crypto APIs.
// Node.js - native crypto, no dependencies import { randomUUID } from 'crypto'; const id = randomUUID(); console.log(id); // → 550e8400-e29b-41d4-a716-446655440000
# Python - stdlib, no pip install needed import uuid id = uuid.uuid4() print(id) # → 550e8400-e29b-41d4-a716-446655440000
// Go - using google/uuid package import ( "fmt" "github.com/google/uuid" ) id := uuid.New() fmt.Println(id) // → 550e8400-e29b-41d4-a716-446655440000
// Rust - uuid crate with v4 feature use uuid::Uuid; fn main() { let id = Uuid::new_v4(); println!("{}", id); } // → 550e8400-e29b-41d4-a716-446655440000
Ready to integrate?
Explore the REST API, browse implementation guides for your language, or read the full documentation to get started in minutes.