Freedom251 › Embedded Databases
LevelDB
What LevelDB is
LevelDB is an open-source key-value storage library for applications that need to store and retrieve data through a programming interface. It maps string keys to string values and keeps entries ordered by key, with support for custom comparison functions and forward or backward traversal. Its core operations are Put, Get, and Delete; related changes can also be grouped into atomic batches. A transient snapshot provides a consistent view of the stored data. LevelDB compresses data with Snappy and supports Zstd as well. The project describes its main aim as providing a reliable, fast key-value store. It runs on Linux, macOS, and Windows. The repository describes POSIX builds for Linux and macOS, and a Windows build using CMake and Visual Studio. Documentation is available online and with the source code. LevelDB is free under the BSD-3-Clause license. Its design does not include SQL queries, a relational data model, indexes, or built-in client-server support. Only one process can access a database at a time, and the repository describes maintenance as very limited, with review focused on critical fixes and changes needed by internally supported clients.
Who it suits
LevelDB suits developers who need a free key-value store with ordered data, atomic batches, and snapshots. It fits applications that can use an API and operate within its single-process access model.
What it does well
- Free and open source under the BSD-3-Clause license
- Stores string keys and values in sorted order
- Supports atomic batches of changes
- Offers transient snapshots for consistent reads
- Supports Snappy and Zstd compression
- Documentation is online and bundled with the source
What to know first
- No SQL queries, relational model, or indexes
- No built-in client-server support
- Only one process can access a database at a time
- The project describes maintenance as very limited
Limits
LevelDB is free under the BSD-3-Clause license. Its design allows access by only one process at a time and has no SQL, relational model, indexes, or built-in client-server support.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| LevelDB | Fast key-value storage library · BSD-3-Clause license | Free |
As github.com lists them, read 4 Oct 2026. The maker's own page has the final word.
Getting started
- Visit the LevelDB GitHub repository.
- Choose the build route for Linux or macOS, or use CMake and Visual Studio on Windows.
- Build the library for your platform.
- Use the API and consult the online or bundled documentation.
Verdict
Choose LevelDB if your application needs an API-based key-value store with ordered data, atomic batches, and snapshots. Look elsewhere if you need SQL, indexes, built-in client-server access, or simultaneous database access by multiple processes.
Questions
How much does LevelDB cost?
LevelDB is free. Its plan is listed as free.
Is LevelDB open source?
Yes. The repository identifies its license as BSD-3-Clause.
Which platforms does LevelDB support?
Linux, macOS, and Windows are supported. The repository describes POSIX builds for Linux and macOS and a Windows build using CMake and Visual Studio.
How does LevelDB store and query data?
It maps string keys to string values and provides Put, Get, and Delete operations through an API. It does not provide SQL queries or a relational data model.
Can multiple processes access a LevelDB database at once?
No. Only one process can access a database at a time.
Who makes LevelDB?
LevelDB is available from the Google GitHub repository.
Facts from LevelDB's own pages
- Compression
- LevelDB compresses data using Snappy and also supports Zstd compression. · github.com, 4 Oct 2026
- Data operations
- Its basic operations are Put, Get, and Delete, and it supports atomic batches of changes. · github.com, 4 Oct 2026
- Documentation
- Library documentation is available online and bundled with the source code. · github.com, 4 Oct 2026
- Intended use
- The project describes its primary goal as being a reliable and fast key-value store. · github.com, 4 Oct 2026
- License
- The repository identifies its license as BSD-3-Clause. · github.com, 4 Oct 2026
- Limitations
- LevelDB has no SQL queries, relational data model, indexes, or built-in client-server support, and only one process can access a database at a time. · github.com, 4 Oct 2026
- Maintenance
- The repository says it receives very limited maintenance and reviews critical bug fixes and changes needed by internally supported clients. · github.com, 4 Oct 2026
- Ordering and reads
- Data is sorted by key, supports custom comparison functions, and can be traversed forward or backward. · github.com, 4 Oct 2026
- Platforms and build
- The README describes POSIX builds for Linux and macOS and a Windows build using CMake and Visual Studio. · github.com, 4 Oct 2026
- Purpose
- LevelDB is a fast key-value storage library that provides an ordered mapping from string keys to string values. · github.com, 4 Oct 2026
- Snapshots
- Users can create a transient snapshot to get a consistent view of data. · github.com, 4 Oct 2026
Where LevelDB stands on Freedom251
- Embedded Databases#10 of 30