Question 1

How to generate a random UUID v4 in Elixir?

Accepted Answer

Use UUID.uuid4() for the standard format or UUID.uuid4(:hex) for a hex string without dashes. It's compliant with RFC 4122 and easy to integrate into any Elixir application.

Question 2

What's the difference between UUID v3 and v5 in Elixir UUID?

Accepted Answer

UUID v3 uses MD5 hashing, while v5 uses SHA-1; both are deterministic based on a namespace and name. V5 is more secure due to SHA-1, but v3 is faster for less critical applications.

Question 3

Elixir UUID or Ecto's built-in UUID type – which should I use?

Accepted Answer

Elixir UUID is a general library for generation and manipulation, while Ecto's type is for database schemas. Use Elixir UUID if you need utility functions or non-database UUIDs; for simple Ecto integrations, the built-in type might suffice but may lack features.

Question 4

How to parse a UUID string and check its version?

Accepted Answer

Call UUID.info/1 for a safe {:ok, info} tuple or UUID.info!/1 to raise on error. It returns a keyword list with :version and other details like variant and format.

Question 5

Can I use custom namespaces with UUID v5 in Elixir UUID?

Accepted Answer

Yes, pass any valid UUID string as a namespace to uuid5/2, in addition to standard atoms like :dns. This allows flexible deterministic UUID generation for custom domains.

Question 6

Is Elixir UUID thread-safe for concurrent use?

Accepted Answer

Yes, as a pure Elixir library leveraging Erlang's concurrency model, it's safe for concurrent environments like Phoenix applications without race conditions.

uuid

What is uuid?

Overview

Use Cases

Best For

Related Projects

Found a gem we're missing?

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions