UUID Version
UUID v5 Generator
Create version-5 UUIDs from a name and a namespace using SHA-1. Like v3, v5 is deterministic — the same inputs always produce the same UUID — but uses a stronger hash.
Name-based v5 (RFC 4122)SHA-1 hashingDeterministic output
Generated locally with the Web Crypto API — nothing leaves your browser.
What Is UUID v5 Generator?
- A UUID v5 hashes a namespace UUID with a name using SHA-1, then sets the version and variant bits. The same namespace + name always yields the same UUID, just like v3 — but with SHA-1 instead of MD5.
- This page uses the DNS namespace with the name
example.comby default. SHA-1 (160 bits) is stronger than the MD5 (128 bits) used by v3, so v5 is the recommended name-based version in modern systems.
How to generate
- Set how many UUIDs you need.
- Toggle uppercase, hyphens and braces as needed.
- Press Generate to compute the deterministic v5 value(s).
Use Cases
- Stable IDs from canonical names (domains, emails, URLs).
- Reproducible keys across services that share a naming scheme.
- Replacing auto-increment IDs with content-derived identifiers.
How UUID v5 Generator Compares
| UUID v5 | SHA-1 name-based; deterministic, recommended |
| UUID v3 | MD5 name-based; deterministic, legacy |
| UUID v4 | Random; not reproducible |
Code Examples
JavaScript
const { v5, v5: ns } = require('uuid');
const id = v5(ns.DNS, 'example.com');Python
import uuid
id = uuid.uuid5(uuid.NAMESPACE_DNS, 'example.com')Frequently Asked Questions
When should I use v5 instead of v3?
Almost always prefer v5. It uses SHA-1, which is the modern recommendation for name-based UUIDs; v3 exists mainly for compatibility with older systems.
Is v5 reproducible?
Yes — given the same namespace and name it always returns the identical UUID, which is exactly why it is used for stable cross-system references.
Does the output reveal the name?
No. The hash is one-way: you cannot recover the original name from the UUID, only verify a candidate name produces the same value.