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Identifiers & Cryptography

ULID Generator

Generate standards-compliant 128-bit ULIDs, bulk generate up to 100 sortable IDs, inspect embedded millisecond timestamps, and decode Crockford Base32.

  • Processed locally
  • No upload required
  • No account required

Generate Standards-Compliant ULIDs

Universally Unique Lexicographically Sortable Identifiers using 128-bit Crockford Base32 encoding.

Quantity:
Showing 5 generated ULIDs
#101M24J0GXNR65M2FVQXX9AQW5Y
#201M24J0GXPZWB38YAPABP0VETX
#301M24J0GXPZWB38YAPABP0VETY
#401M24J0GXPZWB38YAPABP0VETZ
#501M24J0GXPZWB38YAPABP0VEV0

ULID Timestamp Extractor & Inspector

ULID vs. UUID v4 vs. UUID v7 Reference

PropertyULIDUUID v7UUID v4
Format & Encoding26-char Crockford Base3236-char Hex + hyphens36-char Hex + hyphens
SortabilityLexicographically sortableTime-ordered sortableUnsorted random
Timestamp Precision48-bit (millisecond)48-bit (millisecond)None
Entropy / Randomness80 bits74 bits122 bits
URL / Safe charactersCase-insensitive, no I/L/O/URequires lowercase hexRequires lowercase hex

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About ULID Generator & Inspector – Standards-Compliant 128-Bit IDs

Generate Universally Unique Lexicographically Sortable Identifiers (ULID) with cryptographic randomness.

Bulk generate up to 100 sortable keys, export plain text files, and decode embedded millisecond timestamps.

Input is processed locally in your browser and is not sent to Navorika.

How the calculation works

128-Bit Crockford Base32 Structure

A ULID consists of a 48-bit UNIX timestamp (10 characters) followed by 80 bits of cryptographic randomness (16 characters).

Monotonic Sequencing

Multiple ULIDs created within the same millisecond increment the random payload to maintain strict lexicographical ordering.

How to use this tool

  1. 1Select the desired count (1, 5, 10, 25, 50, or 100) and click Generate New.
  2. 2Copy individual ULIDs, copy all generated keys, or download a .txt file.
  3. 3Switch to the Inspector tab to paste an existing ULID and extract its embedded UTC timestamp and randomness payload.

Understanding the result

ULIDs sort alphabetically in chronological order of creation, preventing database index fragmentation.

The 10-character timestamp component can be converted into an exact calendar date and millisecond time.

Important limitations

  • ULIDs are 128-bit identifiers and require 26 characters in Crockford Base32; they do not use standard UUID hyphens.
  • Randomness depends on client Web Crypto API availability.

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Frequently asked questions

How is ULID different from UUID v4?

UUID v4 is entirely random and creates index fragmentation in B-trees. ULID begins with a 48-bit timestamp, ensuring natural chronological sorting.

Why does ULID use Crockford Base32?

Crockford Base32 excludes characters I, L, O, and U to prevent human transcription errors with 1 and 0, and avoids hyphenation.

Can I extract the creation timestamp from a ULID?

Yes. The first 10 characters encode the millisecond Unix timestamp, which can be extracted at any time without database lookups.

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