Open-Source Databases · typicode

lowdb

lowdb is a lightweight, file-based JSON database for Node.js and browsers that stores data as plain JSON files. It requires no server setup, works out-of-the-box with JavaScript objects, and supports TypeScript type safety.

Talk to DEV.co Discuss Implementation

Source: GitHub — github.com/typicode/lowdb

22.6k

GitHub stars

966

Forks

JavaScript

Primary language

MIT

License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

Field	Value
Repository	typicode/lowdb
Owner	typicode
Primary language	JavaScript
License	MIT — OSI-approved
Stars	22.6k
Forks	966
Open issues	15
Latest release	v7.0.0 (2023-12-26)
Last updated	2026-03-27
Source	https://github.com/typicode/lowdb

What lowdb is

lowdb is a pure ESM package providing Low and LowSync classes with pluggable adapters for JSON, localStorage, and custom backends. It performs atomic writes, exposes db.data as a plain JavaScript object, and automatically switches to in-memory mode during tests.

Quickstart

Get the lowdb source

Clone the repository and explore it locally.

terminalbash

1git clone https://github.com/typicode/lowdb.git2cd lowdb3# follow the project's README for install & configuration

Need it deployed, integrated, or customized instead? DEV.co ships production installs.

Best use cases

Electron desktop applications

Ideal for storing application state, settings, and user data in local JSON files without external dependencies or database server complexity.

CLI tools and scripts

Simple persistence layer for configuration, cache, and state in command-line utilities where lightweight file-based storage is sufficient.

Prototyping and small-scale web apps

Rapid development of low-traffic web applications, mockups, or personal projects where schema-less JSON storage meets requirements and scalability is not a constraint.

Implementation considerations

Entire database loads into memory on each read; structure your schema to minimize object size for acceptable performance.
Use db.update() or explicit db.read()–db.write() calls to ensure atomic, safe persistence; ad-hoc writes can corrupt state if interrupted.
lowdb is pure ESM; confirm your build tooling and Node version support ES modules before integration.
For TypeScript projects, leverage the type-safe Data pattern to catch schema errors at compile time.
In-memory mode automatically activates during tests; no explicit configuration needed for unit test acceleration.

When to avoid it — and what to weigh

High concurrency or multi-process workloads — lowdb explicitly does not support Node's cluster module; concurrent writes from multiple processes or heavy parallelism will cause data loss.
Large datasets or memory-constrained environments — The entire database is loaded into memory; objects ~10–100 MB and above may hit performance limits or exhaust available RAM.
Complex querying or relational data — lowdb is not a relational database; queries rely on native JavaScript Array functions. Complex joins, transactions, and normalized schemas are not supported.
Production systems requiring guaranteed ACID compliance — While atomic writes are supported, lowdb lacks transaction semantics, audit logging, and recovery mechanisms expected in mission-critical systems.

License & commercial use

MIT (MIT License) – permissive, allows commercial use, modification, and distribution with proper attribution.

MIT license permits unrestricted commercial deployment, provided the license and copyright notice are retained. No patent grants or liability disclaimers beyond standard MIT terms. Review your organization's OSS policy to confirm acceptability.

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

Signal	Assessment
Maintenance	Active
Documentation	Strong
License clarity	Clear
Deployment complexity	Low
DEV.co fit	Good
Assessment confidence	High

Security considerations

lowdb does not encrypt data by default; plain JSON files are readable by any process with file access. Use DataFile adapter with custom parse/stringify logic (e.g., AES-GCM) for encryption at rest. No built-in input validation; sanitize external data before writes to avoid injection. Browser adapters (localStorage, sessionStorage) are subject to same-origin policy and local storage quota limits; no confidentiality for user-stored data.

Alternatives to consider

SQLite / better-sqlite3

Mature, queryable relational database with ACID transactions and cluster support; heavier than lowdb but suitable for production workloads and complex schemas.

MongoDB / Atlas

Schemaless document database with horizontal scaling, aggregation pipelines, and cloud hosting; introduces network latency and operational overhead unsuitable for simple local persistence.

TinyDB (Python) / RocksDB

Alternative key-value or document stores for other languages; RocksDB offers high-performance embedded storage but requires C++ integration and more complex API.

Software development agency

Build on lowdb with DEV.co software developers

Contact our team to assess fit for your architecture, benchmark performance with your data size, and explore integration strategies.

Talk to DEV.co

Related open-source tools

Surfaced by semantic similarity across the DEV.co open-source index.

tinydb atdatabases electrodb

Related on DEV.co

Explore the category and the services that help you build with it.

Open-Source Databases Application Development Web App Development API Development Talk to DEV.co

lowdb FAQ

Does lowdb support multiple processes writing simultaneously?

No. lowdb does not support Node's cluster module. Concurrent writes from multiple processes will corrupt data. Use a client-server architecture or database server for multi-process workloads.

Can I query data without loading the entire file into memory?

No. lowdb is an in-memory database backed by file storage; the full JSON is loaded on read(). For very large datasets, consider SQLite or a dedicated database.

Is data encrypted or validated?

No built-in encryption or validation. Use custom adapters (DataFile) to add encryption, and pair with schema libraries (Zod, Joi) for runtime validation.

What happens if the process crashes during a write?

Atomic writes reduce the risk, but data may be lost or partially written if the OS is killed during write. For critical data, implement redundancy or use a transactional database.

Work with a software development agency

Adopting lowdb is usually one piece of a larger software development effort. As a software development agency, DEV.co provides software development services and web development expertise — pairing senior software developers and web developers with your team to design, build, and operate open-source databases software in production.

Ready to evaluate lowdb for your project?

Contact our team to assess fit for your architecture, benchmark performance with your data size, and explore integration strategies.

Talk to DEV.co Schedule a Consultation