# ullmark/hashids.net

A small .NET package to generate YouTube-like hashes from one or many numbers. Use hashids when you do not want to expose your database ids to the user.

Repository: https://github.com/ullmark/hashids.net
Canonical: https://ross.abutalabs.com/products/hashidsnet
Homepage: http://www.hashids.org/net/
Language: C#
License: MIT
License Family: permissive
Topics: hashids, decoding, encoding, c-sharp
Last push: 2023-10-25T08:52:13+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 5070, "days_push": 1043, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3354, forks 172 (observed 2026-08-28T04:07:57.902252+00:00)

## What it is
A small .NET (C#) library that encodes integers into short, YouTube-like reversible string IDs (e.g. 347 -> yr8) and decodes them back, with support for salts, custom alphabets, and minimum hash lengths. It is the original Hashids implementation for .NET, now feature-complete and superseded by Sqids.

## Use cases
- hide database ids from users in urls
- generate short unique ids from numbers in c#
- encode multiple numbers into one short string
- create unguessable non-sequential ids for incremental input
- generate url-safe short ids without profanity
- bundle several parameters into a single id

## When to choose
- you are on .NET and need reversible, obfuscated numeric ids
- you want a battle-tested, feature-complete library with stable behavior
- you need custom salt and alphabet support for app-unique ids

## When to avoid
- you need cryptographic hashing or encryption - ids are reversible
- you need to encode negative numbers
- you are starting a new project - the readme recommends sqids-dotnet instead
- you need new features - the library only accepts bug fixes

## Facets
- artifact type: library
- maturity: maintenance
- function: serialization, security
- domain: developer-tools, web-development, databases
- platform: dotnet, cross-platform
- tags: hashids, id-obfuscation, short-ids, encoding, decoding, nuget

## Member repositories
- ullmark/hashids.net (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:57.902252+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 2026-08-29T18:40:56.774039+00:00, confidence not recorded.
  - readme: https://github.com/ullmark/hashids.net (fetched 2026-08-28T04:07:57.902252+00:00, sha 8e4c8a303752)
  - homepage: http://www.hashids.org/net/ (fetched 2026-08-29T09:33:58.370802+00:00, sha 5e6bee61ea41)
  - site_page: https://sqids.org/faq (fetched 2026-08-29T09:33:58.379799+00:00, sha e604ee26ebd8)
- Data as of 2026-08-30T08:39:29.467469+00:00.