LMDB vs redb
LMDB: Tiny memory-mapped B+tree with ACID transactions and lock-free readers; reached 1.0 in 2026. redb: Pure-Rust embedded key-value store: copy-on-write B-trees, ACID, and a stable file format.
key differences
- LMDB is built for larger datasets (≤ 10 TB) than redb (≤ 100 GB).
choose lmdb for
- +Read-heavy embedded indexes and caches
- +Directory services (OpenLDAP back-mdb)
- +Blockchain and wallet state
- +ML dataset storage with fast random reads
best at · Embedded, Metadata, Local-first
choose redb for
- +Local persistence for Rust desktop and CLI apps
- +Embedded metadata and index storage in Rust services
- +Replacing sled or LMDB bindings in Rust code
best at · Embedded, Local-first, Metadata
LMDB vs redb: FAQ
What is the difference between LMDB and redb?
LMDB: Tiny memory-mapped B+tree with ACID transactions and lock-free readers; reached 1.0 in 2026. redb: Pure-Rust embedded key-value store: copy-on-write B-trees, ACID, and a stable file format. LMDB is built for larger datasets (≤ 10 TB) than redb (≤ 100 GB).
When should I choose LMDB over redb?
Choose LMDB for read-heavy embedded indexes and caches; directory services (OpenLDAP back-mdb); and blockchain and wallet state. Choose redb for local persistence for Rust desktop and CLI apps; embedded metadata and index storage in Rust services; and replacing sled or LMDB bindings in Rust code.
Is LMDB or redb more popular?
LMDB ranks #47 on the WhichDB Score (39.7/100) and redb ranks #245 (13.8/100). Popularity is not fit: check the requirements that matter for your project.
Are LMDB and redb open source?
Yes. LMDB is open source. License: OpenLDAP Public License 2.8. Yes. redb is open source. License: MIT or Apache License 2.0.