Text & Encoding

UUID & ID generator tools

Choosing an ID format for a new database table, figuring out what timestamp is hiding inside an ID you didn't generate yourself, or just needing a quick random string for a test fixture — ID generation looks simple until you need one with specific properties like sortability or embedded time data. These tools generate and decode UUIDs, ULIDs, Snowflake IDs, MongoDB ObjectIds and a few newer formats side by side.

UUID generator covers versions v1 through v7, including the deterministic v3 and v5 variants for generating the same ID from the same name every time. ULID generator produces IDs that sort chronologically by default, which plain UUIDs don't. When you're handed an ID instead of creating one, UUID decoder, Snowflake ID decoder and ObjectId generator all extract the embedded timestamp and other fields so you can see when it was actually created.

8 tools

Generate and decode UUIDs

ULID, Snowflake, ObjectId & more

Random strings and timestamps

UUID / ID Generators tools FAQ

Which UUID version should I use for a new database primary key?

UUID v4 is fully random and the most common default. UUID v7 embeds a timestamp so IDs sort roughly by creation time, which helps database index performance over v4's random ordering — UUID generator here supports both, along with v1, v3, v5 and v6 for other cases.

How do I find the creation time hidden inside a Snowflake ID or MongoDB ObjectId?

Both formats embed a timestamp in their structure — Snowflake IDs pack it into the leading bits alongside a node ID, and ObjectIds start with a 4-byte Unix timestamp. Snowflake ID decoder and ObjectId generator both extract the embedded timestamp directly so you don't have to bit-shift it out by hand.

What's the difference between a UUID and a ULID?

A UUID is fixed-length and, in its common v4 form, fully random with no inherent order. A ULID encodes a timestamp in its first characters, so ULIDs generated later always sort after earlier ones as plain strings — ULID generator also supports the monotonic variant for IDs created within the same millisecond.