10 Best Free Database Software of 2026

1. 1

   PostgreSQL

   Open source object-relational database with nearly 40 years of development and a liberal BSD-style license.

   9.9overall

   Open source object-relational database with nearly 40 years of development and a liberal BSD-style license.

   Best forDevelopers and small teams who want one free relational database that can run anything from a side project to production apps.

   Adoption data

   57.9%In the 2026 Stack Overflow Developer Survey, 57.9% of the 12,061 respondents to the database question had done extensive development work in PostgreSQL over the past year, the highest share of any database.

   Stack Overflow, Databases, Technology data 2026, Stack Overflow Developer Survey (2026): “PostgreSQL 6,984 57.9%”

   PostgreSQL is the default free database for most new projects, and the numbers back that up. In the 2026 Stack Overflow survey, 57.9% of respondents had done extensive work with it in the past year, well ahead of SQLite at 42.1% and MySQL at 35.1%. The project describes itself as an open source object-relational system with nearly 40 years of development, ACID compliance since 2001 and support for all major operating systems. It is also unusually extensible: you can define your own data types and functions and add extensions such as PostGIS for geospatial data. As of version 18, it conforms to at least 170 of the 177 mandatory SQL:2023 Core features. The license is a short BSD-style text, and the maintainers say they remain committed to keeping PostgreSQL free and open source in perpetuity. The tradeoff is operations. It is a server you install, tune, back up and upgrade, and help comes from the community or a paid vendor rather than a bundled support plan.

   Strengths

   • +Most used database in the 2026 Stack Overflow survey at 57.9%
   • +Permissive license with a stated commitment to stay free and open source
   • +Extensible enough to cover relational, geospatial and custom workloads

   Limitations

   • −You run a server process and handle backups and upgrades yourself
   • −Support comes from the community unless you hire a vendor
   • −More settings to learn than an embedded engine such as SQLite

   SummaryPostgreSQL pairs the widest developer adoption with a permissive license and deep features. For most developers and small teams it is the best free database to start with.

2. 2

   SQLite

   Public domain, serverless SQL engine that stores a full database in a single file inside your application.

   9.2overall

   Public domain, serverless SQL engine that stores a full database in a single file inside your application.

   Best forApp, desktop and embedded developers who want a zero-configuration database with no server to run.

   Adoption data

   42.1%In the 2026 Stack Overflow Developer Survey, 42.1% of the 12,061 respondents to the database question had done extensive development work in SQLite over the past year, second only to PostgreSQL.

   Stack Overflow, Databases, Technology data 2026, Stack Overflow Developer Survey (2026): “SQLite 5,083 42.1%”

   SQLite is a different kind of database from the servers on this list, and that is its strength. The project describes it as an in-process library that implements a self-contained, serverless, zero-configuration, transactional SQL engine. A full database with tables, indices, triggers and views sits in one cross-platform file that you can copy between machines, and the US Library of Congress recommends the format for storage. Transactions are ACID even after power loss, a database can reach 281 terabytes, and the library can be under 900KiB. Its code is in the public domain, so it is free for any commercial or private use with no license to track. In the 2026 Stack Overflow survey, 42.1% of respondents had worked extensively with it. The limits follow from the design. With no separate server process, SQLite is not meant for many networked clients writing at once, and it lacks server features such as user accounts and built-in replication.

   Strengths

   • +Public domain, so there are no license terms to track
   • +Nothing to install or administer beyond a library
   • +Used by 42.1% of surveyed developers in 2026

   Limitations

   • −No separate server process, so it is not built for many remote clients
   • −Fewer server-side features such as user accounts and replication
   • −The project does not accept outside patches without a public domain affidavit

   SummarySQLite is the best free choice when the database belongs inside your app. Pick a server such as PostgreSQL once many users or services need to share the data.

3. 3

   MySQL Community Edition

   Oracle's freely downloadable, GPL-licensed edition of the MySQL relational database server.

   9.1overall

   Oracle's freely downloadable, GPL-licensed edition of the MySQL relational database server.

   Best forWeb developers on PHP and CMS stacks who want the database their hosts and tools support by default.

   Adoption data

   35.1%In the 2026 Stack Overflow Developer Survey, 35.1% of the 12,061 respondents to the database question had done extensive development work in MySQL over the past year.

   Stack Overflow, Databases, Technology data 2026, Stack Overflow Developer Survey (2026): “MySQL 4,235 35.1%”

   MySQL Community Edition is the free version of what Oracle calls the world's most popular open source database, and it remains a core part of web development. Oracle describes it as freely downloadable, available under the GPL and supported by a large community of open source developers. The reference manual states plainly that anyone can download MySQL and use it without paying anything, and that it can run on a desktop next to other applications, take over a dedicated machine, or scale to clusters of networked servers. It is relational, with rules for relationships between tables that the database enforces. In the 2026 Stack Overflow survey, 35.1% of respondents had worked extensively with MySQL, third behind PostgreSQL and SQLite. The catches are licensing and ownership. If you want to embed MySQL in a commercial closed-source product, Oracle asks you to buy a commercial license, and some tools are reserved for paid editions. Teams that want a community-governed fork often pick MariaDB instead.

   Strengths

   • +Used by 35.1% of surveyed developers in 2026
   • +Free to download and use under the GPL
   • +Widely supported by web hosts and frameworks

   Limitations

   • −Embedding it in closed-source software needs a commercial license
   • −Some features are reserved for the paid Enterprise Edition
   • −Owned by Oracle, which some teams prefer to avoid

   SummaryMySQL Community Edition is a safe free choice for web apps, with broad host and framework support. Check the GPL terms if you plan to ship it inside proprietary software.

4. 4

   MariaDB Server

   Community-developed relational database from the original MySQL developers, licensed under GPLv2.

   8.9overall

   Community-developed relational database from the original MySQL developers, licensed under GPLv2.

   Best forTeams that want a MySQL-compatible server governed independently of any single vendor.

   Adoption data

   20.3%In the 2026 Stack Overflow Developer Survey, 20.3% of the 12,061 respondents to the database question had done extensive development work in MariaDB over the past year.

   Stack Overflow, Databases, Technology data 2026, Stack Overflow Developer Survey (2026): “MariaDB 2,446 20.3%”

   MariaDB Server is the community answer to MySQL. The MariaDB Foundation says it is made by the original developers of MySQL, designed as an enhanced drop-in replacement, and guaranteed to stay open source. It names Wikipedia, WordPress.com and Google among its users and describes a rich ecosystem of storage engines and plugins, with GIS and JSON features in recent versions. The license promise is the main reason to choose it over MySQL: the foundation states that MariaDB Server will remain free and open source software under GPLv2, independent of any commercial entity. In the 2026 Stack Overflow survey, 20.3% of respondents had worked extensively with MariaDB, which puts it sixth among all databases and ahead of MongoDB. The caveats are modest. The two projects have diverged over the years, so check the foundation's compatibility notes if you depend on recent MySQL-only features, and plan for community support unless you pay a vendor.

   Strengths

   • +Committed to staying free and open source under GPLv2
   • +Easy move from MySQL for many applications
   • +Used by Wikipedia, WordPress.com and Google, per the foundation

   Limitations

   • −Smaller survey share than MySQL at 20.3%
   • −The foundation publishes separate feature and compatibility notes to check before moving from MySQL
   • −Community support unless you buy from a vendor

   SummaryMariaDB is the best free option for teams who want MySQL compatibility without relying on Oracle. Its GPLv2 commitment makes long-term license risk low.

5. 5

   Redis Open Source

   Free self-managed edition of Redis, the in-memory data store for caching, queues, search and vectors.

   8.8overall

   Free self-managed edition of Redis, the in-memory data store for caching, queues, search and vectors.

   Best forDevelopers who need a fast cache, session store or message stream next to their main database.

   Adoption data

   28.3%In the 2026 Stack Overflow Developer Survey, 28.3% of the 12,061 respondents to the database question had done extensive development work in Redis over the past year.

   Stack Overflow, Databases, Technology data 2026, Stack Overflow Developer Survey (2026): “Redis 3,414 28.3%”

   Redis Open Source is the free, self-managed edition of Redis, and Redis Ltd. is blunt about the price: its open source page says Redis 8.8 is free and lists it at $0 per month. That edition includes more than 480 commands, 18 data structures such as JSON, time series and vector sets, Redis Search for full-text and vector queries, and the Redis Insight GUI. Redis says it can run vector search across more than 1 billion vectors, and streams with consumer groups cover messaging. In the 2026 Stack Overflow survey, 28.3% of respondents had worked extensively with Redis, fourth among all databases. The license needs a careful read. Starting with Redis 8 you can pick RSALv2, SSPLv1 or AGPLv3, and Redis's own legal page says the first two are not open source licenses, so teams that require an OSI license should choose AGPLv3 or look at Valkey. Because data is held in memory, it is usually a companion to PostgreSQL or MySQL rather than the only database.

   Strengths

   • +Free to run anywhere, from a laptop to on-premises servers
   • +Used by 28.3% of surveyed developers in 2026
   • +Covers caching, sessions, queues and search in one engine

   Limitations

   • −Licensed under RSALv2, SSPLv1 or AGPLv3, and Redis says the first two are not open source
   • −Data lives in memory, so large datasets need a lot of RAM
   • −Usually a second database beside a relational store, not a replacement

   SummaryRedis Open Source is the most capable free in-memory store, with search and vectors built in. Check which of its three licenses fits your use before you ship it.

6. 6

   MongoDB Community Edition

   Free, source-available edition of MongoDB's document database for self-managed use.

   8.5overall

   Free, source-available edition of MongoDB's document database for self-managed use.

   Best forDevelopers building apps around flexible JSON-like documents who want to self-host for free.

   Adoption data

   19.0%In the 2026 Stack Overflow Developer Survey, 19.0% of the 12,061 respondents to the database question had done extensive development work in MongoDB over the past year, the highest share for a document database.

   Stack Overflow, Databases, Technology data 2026, Stack Overflow Developer Survey (2026): “MongoDB 2,297 19.0%”

   MongoDB Community Edition is the free way to run the most widely used document database on your own hardware. MongoDB calls it the free, source-available version of MongoDB and says it runs on local machines, private data centers and self-managed cloud environments on Windows, macOS and Linux. Data lives in JSON-like documents, which suits apps whose records change shape often. The current edition brings full-text, vector and hybrid search to self-managed deployments, so you can build search or AI features without a separate engine, and the MongoDB Shell handles CRUD work and aggregation pipelines. In the 2026 Stack Overflow survey, 19.0% of respondents had worked extensively with MongoDB, the top share for a document store. Two points keep it below the relational leaders here. The license is source-available rather than OSI open source, and MongoDB's own page frames Community Edition around local development, prototyping and testing, with enterprise security and management features reserved for paid editions.

   Strengths

   • +Free to download and run on your own machines
   • +Search and vector search included without extra services
   • +Most used document database in the 2026 survey at 19.0%

   Limitations

   • −Source-available license rather than an OSI open source license
   • −Enterprise security and management tools are in paid editions
   • −MongoDB positions it mainly for development, prototyping and testing

   SummaryMongoDB Community Edition is the best free document database, now with built-in search and vector search. Review the source-available license and paid-only features before relying on it in production.

7. 7

   DuckDB

   MIT-licensed analytical SQL database that runs in-process and reads CSV, JSON, Parquet and Iceberg directly.

   8.3overall

   MIT-licensed analytical SQL database that runs in-process and reads CSV, JSON, Parquet and Iceberg directly.

   Best forAnalysts and developers who need fast SQL analytics on local or cloud files without a data warehouse.

   Adoption data

   5.7%In the 2026 Stack Overflow Developer Survey, 5.7% of the 12,061 respondents to the database question had done extensive development work in DuckDB over the past year.

   Stack Overflow, Databases, Technology data 2026, Stack Overflow Developer Survey (2026): “DuckDB 690 5.7%”

   DuckDB is the free choice for analytical work that would otherwise need a paid warehouse. It is an analytical SQL database that runs inside your process, from a laptop to servers with hundreds of cores, and it reads and writes CSV, JSON, Parquet and Iceberg files locally or in object storage. Its SQL dialect is inspired by PostgreSQL, extensions add functions and formats, and there are clients for Python, Go, Java, Node.js, Rust and ODBC. The 2.0 release added Quack, a client-server protocol, and the project also maintains DuckLake, a lakehouse format that uses a SQL database as its catalog. The licensing is as simple as it gets: the FAQ says DuckDB is fully open source under the MIT license, every component is in the free version, and the DuckDB Foundation holds the intellectual property. In the 2026 Stack Overflow survey, 5.7% of respondents had worked extensively with it. It is not a replacement for PostgreSQL as an app database, because it is optimized for scans and aggregates rather than many small writes.

   Strengths

   • +Every component is MIT-licensed, with no enterprise version
   • +Queries files directly without loading them into a server
   • +Governed by the independent DuckDB Foundation

   Limitations

   • −Built for analytics, not for many small transactional writes
   • −Lower survey share than general-purpose databases at 5.7%
   • −Client-server use through Quack is newer than the embedded mode

   SummaryDuckDB is the best free database for analytics on files and notebooks. Pair it with a transactional database rather than using it as your app's main store.

8. 8

   Valkey

   BSD-licensed key-value datastore backed by the Linux Foundation, used for caching, queues and as a primary database.

   8.0overall

   BSD-licensed key-value datastore backed by the Linux Foundation, used for caching, queues and as a primary database.

   Best forTeams that want a Redis-style in-memory store under a permissive open source license.

   Adoption data

   5.0%In the 2026 Stack Overflow Developer Survey, 5.0% of the 12,061 respondents to the database question had done extensive development work in Valkey over the past year.

   Stack Overflow, Databases, Technology data 2026, Stack Overflow Developer Survey (2026): “Valkey 603 5.0%”

   Valkey is the pick for teams that want an in-memory key-value store under a plain permissive license. The project describes itself as an open source, BSD-licensed, high-performance key-value datastore for caching, message queues and primary database use, backed by the Linux Foundation so that it stays open source. Development is active: the 9.1 line, with version 9.1.3 released on October 26, 2026, claims 2.1 million requests per second on a single server thanks to a redesigned I/O threading model, and adds per-database access control lists, JSON-formatted server logs and Lua scripting as a removable module. Companies including Percona offer support and consulting if you want help. In the 2026 Stack Overflow survey, 5.0% of respondents had worked extensively with Valkey, against 28.3% for Redis, so the community is smaller and you will find fewer tutorials written for it by name. If OSI-approved licensing matters more to you than Redis's bundled GUI and search features, Valkey is the cleaner choice.

   Strengths

   • +Permissive BSD license with no edition split
   • +Backed by the Linux Foundation
   • +Service and support partners such as Percona

   Limitations

   • −Smaller survey share than Redis at 5.0%
   • −Fewer bundled extras than Redis Open Source, such as the Redis Insight GUI
   • −In-memory design means large datasets need a lot of RAM

   SummaryValkey is the best free key-value store for teams that want a BSD license and foundation governance. Redis Open Source offers more built-in extras.

9. 9

   CockroachDB

   Distributed SQL database with PostgreSQL compatibility, free to self-host for businesses under $10M in annual revenue.

   6.9overall

   Distributed SQL database with PostgreSQL compatibility, free to self-host for businesses under $10M in annual revenue.

   Best forSmall companies that need a SQL database spread across nodes or regions and stay under the revenue limit.

   Adoption data

   1.0%In the 2026 Stack Overflow Developer Survey, 1.0% of the 12,061 respondents to the database question had done extensive development work in CockroachDB over the past year.

   Stack Overflow, Databases, Technology data 2026, Stack Overflow Developer Survey (2026): “Cockroachdb 117 1.0%”

   CockroachDB is the only distributed SQL database on this list, and it is free for small companies with conditions. Cockroach Labs' licensing FAQ describes an Enterprise Free license with the same functionality as Enterprise, free of charge for businesses with less than $10M in annual revenue. That license must be renewed every year, comes with community support, and clusters are throttled after 7 days without sending telemetry. The product itself is strong: Cockroach Labs documents horizontal scaling for reads and writes by adding nodes, automated rebalancing, hotspot detection, globally consistent transactions and PostgreSQL compatibility with stored procedures and user-defined functions. If you would rather not run it, CockroachDB Cloud Standard starts at $0.092 per vCPU-hour, and new organizations get a 30-day trial with $400 in credit. Adoption is the weak spot: only 1.0% of respondents in the 2026 Stack Overflow survey had worked extensively with it, so hiring and community help are harder to find than for PostgreSQL.

   Strengths

   • +Enterprise features at no charge for businesses under $10M in revenue
   • +Distributed design removes manual sharding
   • +PostgreSQL compatibility eases migration

   Limitations

   • −Free license requires telemetry, and clusters are throttled after 7 days without it
   • −Free license must be renewed every year
   • −Only 1.0% of surveyed developers use it

   SummaryCockroachDB is the free option when you truly need SQL across several nodes or regions. The revenue cap, yearly renewal and telemetry rule make it less free than the open source engines here.

10. 10

    Firebird

    Open source relational database used in production since 1981, free to deploy even inside commercial software.

    6.9overall

    Open source relational database used in production since 1981, free to deploy even inside commercial software.

    Best forDevelopers of Windows and Linux business applications who want a compact SQL server they can ship with their product at no cost.

    Firebird is the long-lived option on this list. The project says it is a relational database with many ANSI SQL features that runs on Linux, Windows and several Unix platforms, and that it has been used in production, under various names, since 1981. It is based on source code Borland released in 2000 and is now developed by a commercially independent team. The pricing promise is the clearest of any entry: no fees for download, registration, licensing or deployment, even when you distribute Firebird inside a commercial software package. Version 5.0 added multithreaded backup, restore and sweep, SQL query profiling and better scalability, and 5.0.4 shipped on April 17, 2026 with builds for Windows, Linux, macOS and Android, including an embedded kit. The weakness is reach. Firebird does not appear among the databases listed in the 2026 Stack Overflow survey, so community answers, managed hosting and hiring are thinner than for PostgreSQL, and development relies on donations and sponsorship.

    Strengths

    • +No fees even when bundled in commercial software
    • +Long production history since 1981
    • +Embedded and server packages across many platforms

    Limitations

    • −Not listed in the 2026 Stack Overflow database survey
    • −Smaller ecosystem of hosting and tools than PostgreSQL or MySQL
    • −Development depends on voluntary funding

    SummaryFirebird suits software vendors who want to ship a free SQL engine with a desktop or on-premises product. Most new projects will find more help with PostgreSQL.

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