whichdb
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LMDB vs MMKV

LMDB: Tiny memory-mapped B+tree with ACID transactions and lock-free readers; reached 1.0 in 2026. MMKV: Tencent's mmap-backed key-value store for mobile apps, built as a faster SharedPreferences/NSUserDefaults.

key differences

  • LMDB is built for larger datasets (≤ 10 TB) than MMKV (≤ 100 GB).
  • Transactions: LMDB offers full ACID; MMKV offers none.
  • Only LMDB has transactions.
  • Only MMKV has ttl / expiry, encryption at rest.

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 mmkv for

  • +Replacing SharedPreferences, NSUserDefaults or AsyncStorage
  • +Feature flags and user settings
  • +Small session and token caches on device

best at · Embedded, Coordination, Cache

LMDBTiny memory-mapped B+tree with ACID transactions and lock-free readers; reached 1.0 in 2026.
MMKVTencent's mmap-backed key-value store for mobile apps, built as a faster SharedPreferences/NSUserDefaults.
overview
Primary model
Key-Value
Key-Value
Also supports
–
–
Type
Embedded library
Embedded library
Status
Active
Active
Developer
Symas Corporation / OpenLDAP Project
Tencent
First release
2011
2018
Latest version
1.0.2 (Sep 8, 2026)
2.4.3 (Oct 16, 2026)
License
Open source (permissive)OpenLDAP Public License 2.8
Open source (permissive)BSD 3-Clause License
Free tier
✓
✓
popularity
WhichDB Score
39.7
6.3
Rank
#47
#364
GitHub stars
3.1K
18.8K
Stack Overflow questions
260
–
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Small (≤ 100 GB)
Horizontal scaling
None
None
Multi-region
None
None
ACID
Full
None
Consistency
Strong
Strong
Schema
Schemaless
Schemaless
Architecture
Embedded
Embedded
deployment
Self-hosted
✓
✓
Vendor-managed cloud
—
—
Serverless
—
—
Embedded
✓
✓
Edge
—
—
Clouds
–
–
capabilities
Transactions
✓
—
Joins
—
—
Secondary indexes
—
—
Full-text search
—
—
Vector search
—
—
Geospatial
—
—
JSON
—
—
Change data capture
—
—
Triggers
—
—
Stored procedures
—
—
Materialized views
—
—
TTL / expiry
—
✓
Pub/Sub
—
—
Columnar storage
—
—
In-memory
—
—
Durable persistence
✓
✓
Compression
—
—
Encryption at rest
—
✓
Role-based access
—
—
Time travel
—
—
Branching
—
—
Online schema changes
—
—
Streaming ingest
—
—
Offline sync
—
—
Runs in WebAssembly
—
—
interfaces
Query languages
C API
Key-value API
Client languages
C, C++, Python, Go, Rust, Java, JavaScript
C++, Java, Kotlin, Objective-C, Swift, Dart, Python, Go
Best for
Embedded, Metadata, Local-first
Embedded, Coordination, Cache, Sessions
Add more to this comparisonNot sure either fits? Try smart match

LMDB vs MMKV: FAQ

What is the difference between LMDB and MMKV?

LMDB: Tiny memory-mapped B+tree with ACID transactions and lock-free readers; reached 1.0 in 2026. MMKV: Tencent's mmap-backed key-value store for mobile apps, built as a faster SharedPreferences/NSUserDefaults. LMDB is built for larger datasets (≤ 10 TB) than MMKV (≤ 100 GB). Transactions: LMDB offers full ACID; MMKV offers none. Only LMDB has transactions.

When should I choose LMDB over MMKV?

Choose LMDB for read-heavy embedded indexes and caches; directory services (OpenLDAP back-mdb); and blockchain and wallet state. Choose MMKV for replacing SharedPreferences, NSUserDefaults or AsyncStorage; feature flags and user settings; and small session and token caches on device.

Is LMDB or MMKV more popular?

LMDB ranks #47 on the WhichDB Score (39.7/100) and MMKV ranks #364 (6.3/100). Popularity is not fit: check the requirements that matter for your project.

Are LMDB and MMKV open source?

Yes. LMDB is open source. License: OpenLDAP Public License 2.8. Yes. MMKV is open source. License: BSD 3-Clause License.