UnQLite
UnQLite is an embedded NoSQL database engine that gives applications key/value and document-store interfaces without a separate server process.
What UnQLite is
UnQLite is an embedded NoSQL database engine that gives applications key/value and document-store interfaces without a separate server process. Applications read and write database files directly, and a database with multiple collections can be held in one ordinary disk file. It supports byte-array key/value data and JSON documents through its embedded Jx9 scripting language, with both on-disk and in-memory storage options. The maker describes its transactions as ACID and serializable, intended to remain atomic through crashes and power failures. Its core sets no database size limit, though the underlying key/value store has its own limit. Thread safety depends on compiling with the UNQLITE_ENABLE_THREADS directive. C and C++ APIs are available, and the software is released under the 2-Clause BSD license. Downloads include source code, documentation, sample programs, and a key/value-only package that omits the Jx9 document-store layer. A proprietary extension is offered for databases encrypted with 128-bit or 256-bit AES.
Good
- Works directly with database files, without a server
- Supports byte-array key/value data and JSON documents
- Offers on-disk and in-memory databases
- Open source under the 2-Clause BSD license
Watch out
- Thread safety requires a compile-time directive
- AES encryption is offered as a proprietary extension
- Professional support is a paid service on request
Who it suits
UnQLite suits developers who need an embedded database with key/value or JSON document storage and no separate server. Its self-contained library is intended for embedded devices and applications running across varied computer configurations.
Verdict
UnQLite combines embedded key/value and document storage with on-disk and in-memory options. Consider its compile-time requirement for thread safety and the separate cost of professional support or the AES extension.
Plans and prices
From UnQLite's own pricing page, checked 8 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| UnQLite open-source software | Free | 2-Clause BSD license · downloadable source code |
| Silver Sponsorship | $15,000 a year | Sponsorship benefits listed by the maker · $15K/Year |
| Gold Sponsorship | $50,000 a year | Enterprise-level technical support · direct source-tree and core-developer access · $50K/Year |
| Platinum Sponsorship | — | Enterprise-level technical support · direct source-tree and core-developer access · $100K/Year |
The facts
Each one read from UnQLite's own pages, with the date it was checked.
What it does
- Capacity
- The FAQ says the UnQLite core imposes no database size limit and that the underlying key/value store determines its own limit.checked 8 Oct 2026
- Data models
- UnQLite supports byte-array key/value data and JSON document storage through the embedded Jx9 scripting language.checked 8 Oct 2026
- Downloads
- The downloads page lists source code, a key/value-only package without the Jx9 document-store layer, documentation, and sample programs.checked 8 Oct 2026
- Integration
- The maker provides C/C++ APIs and documents how to register C/C++ foreign functions and constants for use from Jx9 scripts.checked 8 Oct 2026
- Intended use
- The maker says the self-contained library is suited to embedded devices and applications that need to run across computers with varied configurations.checked 8 Oct 2026
- License
- UnQLite is open-source software released under the 2-Clause BSD license.checked 8 Oct 2026
- Purpose
- UnQLite is an in-process, embedded NoSQL database engine that provides key/value and document-store interfaces.checked 8 Oct 2026
- Security extensions
- The maker offers a proprietary extension for reading and writing databases encrypted with 128-bit or 256-bit AES.checked 8 Oct 2026
- Serverless
- Applications read and write database files directly without a separate server process.checked 8 Oct 2026
- Storage
- A complete database with multiple collections is contained in a single ordinary disk file.checked 8 Oct 2026
- Storage options
- The maker lists both on-disk and in-memory databases and describes a pluggable runtime storage engine.checked 8 Oct 2026
- Support
- Public technical discussions and troubleshooting are directed to GitHub Issues, while professional support is available as a paid service on request.checked 8 Oct 2026
- Thread safety
- The library is thread-safe when compiled with the UNQLITE_ENABLE_THREADS compile-time directive.checked 8 Oct 2026
- Transactions
- The maker describes UnQLite as transactional and ACID, with serializable transactions designed to remain atomic through crashes and power failures.checked 8 Oct 2026
Where it runs
- Platforms
- The ANSI C code is described as running on most platforms with a C compiler and is extensively tested on Windows, Linux, FreeBSD, Oracle Solaris, and Mac OS X.checked 8 Oct 2026
