Isar Database (Dart / Flutter)
| Format | Isar Database (Dart / Flutter) |
|---|---|
| Short name | Isar |
| Category | database |
| Platforms | Windows, macOS, Linux, iOS, Android |
| Crush support | Not yet supported |
| Status | Reviewed |
| Last reviewed | 2026-10-06 |
Forensic relevance
Embedded object database of the Dart/Flutter Isar library. Isar 3.x and its community fork store each instance in a single libmdbx file named <name>.isar (default.isar for the default instance) with a <name>.isar-lck lock file next to it. The file is a libmdbx database and carries the libmdbx meta page signature (see LMDB / libmdbx Database); only the name and its sub-databases tell it apart. Each collection is a named sub-database keyed by the 64-bit object ID, accompanied by sub-databases for indexes (_i_<collection>_<index>) and links (_l_ and _b_ prefixes). The _info sub-database holds the collection schemas as JSON, which gives the property names and types needed to decode the binary objects. Collections hold the app's structured records, for example libraries, histories, download lists or account data, depending on the app. Objects use a compact little-endian layout of a static part followed by dynamic data; DateTime values are stored as UTC microseconds since the Unix epoch. As in any libmdbx file, freed pages can retain deleted or earlier versions of objects until they are reused or the file is compacted (rewritten as <name>.isar.compact and renamed, only when the app enables compaction on open). Isar 3 has no encryption. Isar 4 (development releases and forks) can use this native engine or SQLite; with SQLite the instance is a <name>.sqlite file in WAL mode, optionally encrypted with SQLCipher. Found in the app data directories of Flutter apps on Android, iOS and desktop systems.
Signatures
| Offset | Hex | ASCII (non-printable as .) | Description |
|---|---|---|---|
| offset unknown | 03 11 4C EF BD 9D 65 59 | ..L...eY | libmdbx meta page signature at offset 20, shared with every libmdbx file (see LMDB / libmdbx Database); identifies the storage engine, not Isar |
Known extensions
.isar
References
- Isar 3.1.0+1 instance: file name, sub-databases, compaction (source) https://github.com/isar/isar/blob/3.1.0%2B1/packages/isar_core/src/instance.rs
- Isar 3.1.0+1 libmdbx environment flags (source) https://github.com/isar/isar/blob/3.1.0%2B1/packages/isar_core/src/mdbx/env.rs
- Isar 4 SQLite engine: file name, WAL, encryption (source) https://github.com/isar/isar/blob/main/packages/isar_core/src/sqlite/sqlite_open.rs
- Isar Community (maintained fork of Isar 3) https://github.com/isar-community/isar-community
Cite this entry
Crush Format Reference, “Isar Database (Dart / Flutter)”. https://kalink0.github.io/crush-forensics/formats/isar/ — source: crush/data/build_formats_db.py at commit 640a2a9928f4e36a976b89901512a8dce824d093, built 2026-10-21 06:46:19 UTC.
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