ID generator

Each tile is tagged with the features and trade-offs that distinguish that format — capabilities you can rely on alongside caveats worth knowing about.

Time-sortable. The timestamp sits at the front of the ID, so byte order matches creation order — great for database keys and pagination. Applies to UUID v6, v7, ULID, KSUID, CUID, Snowflake, TSID, XID, and ObjectID. (UUID v1 and v2 carry a timestamp but split it across fields, so byte order does not match creation order — that is exactly what v6 reorders.)

URL-safe. The encoding uses only characters that need no escaping in URLs — typically Crockford base32 or lowercase alphanumerics. ULID, KSUID, NanoID, CUID, CUID2, TSID, and XID qualify.

64-bit. The ID fits in a 64-bit integer column (BIGINT), useful when storage size or numeric indexing matters. Snowflake and TSID are 64-bit; the rest are 96-bit or larger.

Deterministic. The same inputs always produce the same ID — hashing a namespace + name with MD5 (v3) or SHA-1 (v5). Anyone with the inputs can recompute the ID, so it is not unguessable.

Custom layout. The bits inside the ID are application-defined; only the UUID version and variant fields are fixed. UUID v8 is the only format with this tag.

Embeds host id. A machine, MAC, or process fingerprint is encoded into the ID, so anyone who sees it can identify or correlate the generator. UUID v1, XID, and ObjectID all do this.

Legacy. The format is deprecated, superseded, or reserved-only — prefer a modern alternative for new systems. Applies to UUID v1, v2, v3 (broken MD5), and CUID v1.

Random bytes come from crypto.getRandomValues, the browser's CSPRNG. Timestamps come from Date.now() and performance.now() where sub-millisecond precision matters. Everything happens in your tab — no ID is sent anywhere.