CUID Generator
Generate CUID-style (Collision-Resistant Unique ID) identifiers in your browser. CUIDs combine a timestamp with random characters to create IDs that are both unique and roughly sortable by creation time. Each ID starts with 'c' followed by the timestamp in base-36 and random characters.
The timestamp component means IDs generated close together will sort near each other, which is valuable for database indexing and time-ordered data. The random component ensures uniqueness even when multiple IDs are generated in the same millisecond.
Generate single IDs or batch-generate multiple at once. All randomness comes from the browser's crypto.getRandomValues API — no server, no external dependencies.
By The Paper Room Editorial Team — Developer Tools
Frequently asked questions
What makes CUIDs collision-resistant?▼
CUIDs combine a millisecond timestamp with cryptographically random characters. Even if two IDs are generated in the same millisecond on the same machine, the random component makes collisions extremely unlikely.
Are CUIDs sortable?▼
Roughly, yes. Because they start with a timestamp component, CUIDs generated later will generally sort after earlier ones. This makes them friendlier for database B-tree indexes compared to fully random UUIDs.
How long is a generated CUID?▼
The generated IDs are 25 characters long: a 'c' prefix, 8 characters of base-36 timestamp, and 16 random characters. This provides a good balance between compactness and collision resistance.