UUID vs. Auto-Incrementing IDs: Which is Better?

Every database table needs a primary key. The traditional choice is an auto-incrementing integer. But in distributed systems, UUIDs (Universally Unique Identifiers) are gaining popularity.

Auto-Increment

Pros: Small storage size, fast indexing, human-readable.

Cons: Predictable (hackers can guess /user/100 exists if /user/99 does), hard to merge databases.

UUID

Pros: Globally unique (can generate offline), secure (unpredictable), easy to merge data.

Cons: Larger storage size (128-bit), slightly slower indexing.

Verdict

For public-facing resources (like user profiles or order IDs), use UUIDs to prevent enumeration attacks. Generate them with our tool.