Generate UUID v5

Create a deterministic UUID from a namespace and UTF-8 name.

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ToolUUID v5 Generator
Input
Output
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How it works

The namespace UUID and name bytes are hashed with SHA-1, truncated to 128 bits, and marked with version and variant bits. Reusing the same inputs reproduces the same UUID.

  • Stable output suits repeatable identifiers.
  • The namespace separates otherwise equal names in different domains.

Worked example

DNS Namespace
Generate a UUID v5 for 'example.com' using the DNS namespace
Input
											Name: example.com
Namespace: dns
Custom namespace:
Output
												cfbff0d1-9375-5685-968c-48ce8b15ae17

When to use this

URLs, DNS names, package keys, and migrations generate stable IDs.

Edge cases

  • Case or Unicode normalization changes the input bytes.
  • A different namespace intentionally changes the result.
  • Deterministic hashing is not password protection.

References