# oklog/ulid

Universally Unique Lexicographically Sortable Identifier (ULID) in Go

Repository: https://github.com/oklog/ulid
Canonical: https://ross.abutalabs.com/products/oklog-ulid
Language: Go
License: Apache-2.0
License Family: permissive
Last push: 2026-07-23T19:45:42+00:00

## Health v2 (maintenance only)
Score: 84/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 94, release rhythm 62, longevity 100
- inputs: {"age_days": 3557, "days_push": 41, "days_rel": 41, "gap_med": 427, "n_releases_24m": 2}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 5051, forks 192 (observed 2026-08-28T04:09:09.031921+00:00)

## What it is
A Go library implementing ULID (Universally Unique Lexicographically Sortable Identifier), a 128-bit identifier that is lexicographically sortable and encoded as a 26-character Crockford base32 string. It supports monotonic generation within the same millisecond and flexible entropy sources.

## Use cases
- generate sortable unique ids for database primary keys
- replace uuids with lexicographically sortable identifiers
- generate monotonic ids within the same millisecond
- create url-safe case-insensitive identifiers
- generate ids compatible with uuid size but more compact

## When to choose
- you need ids that sort chronologically in databases or files
- you want a compact, url-safe alternative to uuids
- you need monotonic id generation in Go

## When to avoid
- you need standard uuids for interoperability with existing systems
- you are not working in Go
- you need ids with embedded randomness only and no timestamp

## Facets
- artifact type: library
- maturity: stable
- function: serialization, developer-tools
- domain: developer-tools, databases, backend
- platform: go, cross-platform
- tags: ulid, unique-identifiers, sortable-ids, uuid-alternative, base32

## Member repositories
- oklog/ulid (main) score 84

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:09.031921+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:17:21.279012+00:00, confidence not recorded.
  - readme: https://github.com/oklog/ulid (fetched 2026-08-28T04:09:09.031921+00:00, sha cac811641635)
- Data as of 2026-08-30T08:39:29.467469+00:00.