Possible Alternatives to UUID

While Universally Unique Identifiers (UUIDs) are the industry standard for generating unique keys in distributed systems, they aren't always the best fit for every use case. Whether you need better database performance, URL-friendliness, or sortability, several modern alternatives exist.

Why look for UUID alternatives?

Standard UUIDs (especially Version 4) are excellent for uniqueness but can have drawbacks:

  • Length: At 36 characters, they can be unwieldy in URLs.
  • Database Performance: Random UUIDs can cause fragmentation in clustered indexes (like in MySQL or PostgreSQL) because they aren't sequential.
  • Readability: They are hard for humans to type or dictate.

Let's explore some of the most popular alternatives we support, including CUID, KSUID, NanoID, ULID, and more.

CUID & CUID2

CUID (Collision-Resistant Unique Identifier) was created to solve the problem of horizontal scaling and sequential ID generation in web applications. It is designed to be collision-resistant and k-sortable (roughly time-ordered).

CUID2 is the next evolution, offering even stronger security and collision resistance. It uses a secure entropy source and a hash function to ensure uniqueness.

KSUID (K-Sortable Unique Identifier)

KSUID combines a timestamp with a random payload. The key feature implies by its name: it is K-Sortable, meaning it can be naturally sorted by creation time. This makes it excellent for databases where chronological ordering is important (like Reddit's posts or messaging logs).

NanoID

NanoID is a tiny, secure, URL-friendly unique string ID generator for JavaScript. It is significantly smaller than UUID (usually 21 characters vs 36) but offers similar collision resistance. It uses a larger alphabet (A-Za-z0-9_-) to pack more entropy into fewer characters.

  • Best for: Short URLs, UI-facing IDs, bandwidth-constrained environments.
  • Tools: Generate NanoID

ULID (Universally Unique Lexicographically Sortable Identifier)

ULID aims to be a direct replacement for UUID with sortability. It is encoded in Base32 (URL safe, case insensitive) and sorts correctly as a string. It consists of a 48-bit timestamp and 80 bits of random data.

  • Best for: Replacing UUID v4 where sorting is needed, NoSQL databases (DynamoDB).
  • Tools: Generate ULID

GUID (Globally Unique Identifier)

GUID is essentially the Microsoft implementation of the UUID standard. While often used interchangeably with UUID, GUIDs specifically refer to the identifier type used in the .NET ecosystem and Windows programming. Functionally, they are usually compliant with UUID versions (often v4).

  • Best for: Windows/Microsoft ecosystems, Legacy systems.
  • Tools: Generate GUID

Snowflake ID

Originally developed by Twitter, Snowflake IDs are 64-bit integers (unlike the string-based IDs above). They are composed of a timestamp, a machine ID, and a sequence number. This makes them extremely efficient for database indexing and storage (fitting in a `BIGINT`).

  • Best for: Distributed systems requiring high throughput, microservices, Twitter-scale applications.
  • Tools: Generate Snowflake ID

Short UUID

Sometimes you just need a standard UUID but in a more compact form. Short UUID translators typically encode a standard UUID into Base57 or similar alphabets to reduce the string length while maintaining the ability to convert back to the original UUID.

Conclusion

Choosing the right identifier depends on your specific constraints. For standard use, UUID v4 or UUID v7 (which adds sortability to UUID) are safe bets. However, if you need compactness, NanoID is great. For database primary keys, consider ULID, KSUID, or Snowflake ID to avoid fragmentation.