# Realm Database

Core database component for the Realm Mobile Database SDKs

Repository: https://github.com/realm/realm-core
Canonical: https://ross.abutalabs.com/products/realm-database
Homepage: https://realm.io
Language: C++
License: Apache-2.0
License Family: permissive
Topics: database, mobile-database, realm, c-plus-plus, cpp, library, nosql-database, mobile, realtime-database, reactive
Last push: 2026-06-14T01:55:44+00:00
Link (homepage): https://realm.io

## Health v2 (maintenance only)
Score: 73/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 87, release rhythm 40, longevity 100
- inputs: {"age_days": 5555, "days_push": 81, "days_rel": 544, "gap_med": 15, "n_releases_24m": 10}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1055, forks 220 (observed 2026-08-28T04:03:24.359566+00:00)

## What it is
Realm is an object-oriented mobile database that runs directly on phones, tablets, and wearables, serving as a replacement for SQLite and Core Data. It offers live objects with reactive change notifications, offline persistence, and SDKs for Swift, Java, Kotlin, JavaScript, and .NET.

## Use cases
- store data offline in a mobile app
- replace SQLite or Core Data in an iOS app
- build reactive UIs that update when data changes
- persist objects in an Android app without writing SQL
- use a local database with SwiftUI
- manage app data on wearables and embedded mobile devices

## When to choose
- you need an offline-first local database on mobile platforms
- you want an object-oriented data model without an ORM layer
- you need reactive/live queries that automatically update your UI
- you want a lightweight, battery- and memory-efficient database on phones

## When to avoid
- you need a server-side or multi-client relational database
- your project depends on MongoDB Atlas Device Sync, which is being deprecated
- you need complex SQL queries or joins
- you target platforms without a Realm SDK

## Facets
- artifact type: library
- maturity: active
- function: database, orm, caching, sdk
- domain: mobile-development, databases, cross-platform, developer-tools
- platform: jvm, dotnet, cpp, cross-platform
- tags: mobile-database, offline-first, reactive-queries, live-objects, sqlite-alternative, core-data-alternative, swiftui, thread-safe, realtime-sync, object-database, ios, android, macos, swift, mobile

## Member repositories
- realm/realm-core (main) score 73
- realm/realm-swift (sdk) score 86
- realm/realm-java (sdk) score 51
- realm/realm-js (sdk) score 82
- realm/realm-dotnet (sdk) score 62
- realm/realm-kotlin (sdk) score 54

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:24.359566+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 2026-08-29T17:04:50.695335+00:00, confidence not recorded.
  - readme: https://github.com/realm/realm-core (fetched 2026-08-28T04:03:24.359566+00:00, sha 7dc0c9abbbeb)
  - homepage: https://realm.io (fetched 2026-08-29T08:02:23.435056+00:00, sha 7fe20d311e00)
- Data as of 2026-08-30T08:39:29.467469+00:00.