ULID Generator
Generate sortable ULIDs and decode the timestamp inside any ULID.
ULIDs fix the database-unfriendliness of random UUIDs: the first 10 characters encode a millisecond timestamp, so IDs sort by creation time and cluster nicely in B-tree indexes, while 80 bits of randomness keep them unguessable and collision-resistant. Same 128 bits as a UUID, better ergonomics — 26 case-insensitive characters, no hyphens.
Generate one or many ULIDs using your browser's cryptographic randomness, and decode any existing ULID to reveal its embedded creation timestamp. Everything runs locally.
How to use ULID Generator
- 1
Choose how many to generate
1 for a quick ID, hundreds for seeding data.
- 2
Copy the ULIDs
Each is 26 Crockford-Base32 characters.
- 3
Decode when needed
Paste any ULID to extract its timestamp.
Features
- Cryptographically random 80-bit entropy
- Bulk generation for test fixtures
- Timestamp decoder for existing ULIDs
Frequently asked questions
Common mistakes to avoid
- Treating ULIDs as unguessable secrets — the timestamp half is predictable; use full-entropy tokens for secrets.
- Comparing ULIDs case-sensitively — the spec is case-insensitive; normalize before comparing.
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