Hayz Labs · https://hayzlabs.com/reviews/top/databases/
reviews · top 20 list · checked 19 Oct
Top free databases
Databases you can use for free, either open source you run yourself or a hosted service with a free tier, for the app or AI project you are building.
Nothing on this list is scored yet: no outside source we can turn into a number covers them. The order below follows the public measure named on each row.
By share of developers using it in the Stack Overflow 2026 survey (all respondents). Only databases with a free option are listed; vector databases have their own list. Contains information from the Stack Overflow Developer Survey 2026, which is made available under the Open Database License (ODbL). Open the Table to see the number that placed each one and how it was scored.
- 1PostgreSQLPostgreSQL Global Development Group
A general-purpose relational SQL database you run on your own machine or server
Best for Apps that need reliable SQL storage, JSON documents, and maps data via the PostGIS add-onYou give up Self-hosted: you run, back up and update the server yourself
Not scored yetFree - 2SQLiteSQLite developers (Hwaci)
A small SQL database that lives in one file inside your app, with no server to run
Best for App file formats, phones and devices, small sites, data analysis, testing and teaching SQLYou give up Only one writer at a time per database file; not meant for many clients over a network
Not scored yetFree - 3MySQLOracle
A widely used relational SQL database server; the Community Edition is free to download
Best for Relational data for apps, with replication and clustering in the free Community EditionYou give up GPLv2: shipping it inside closed-source software you sell needs a paid Oracle licence
Not scored yetFree - 4RedisRedis Ltd.
An in-memory data store, most often used as a fast cache or message broker
Best for Caching, message brokering, streams, and document or vector data held in memoryYou give up Open licence is AGPLv3: offer a changed version as a service and you must share the code
Not scored yetFree - 5Microsoft SQL ServerMicrosoft
Microsoft's relational SQL database server. Express is the free edition and may be used in production
Best for Learning, and desktop or small server apps (Microsoft's stated fit for Express)You give up Express caps each database at 50 GB and uses at most 4 cores and 1,410 MB of buffer memory
Not scored yetFree - 6MariaDBMariaDB Foundation and MariaDB plc
A relational SQL database server that began as a community fork of MySQL
Best for Relational data for apps, including apps written for MySQLYou give up GPLv2: an app you ship that needs the server may take on GPL duties; client libs are LGPL
Not scored yetFree - 7MongoDBMongoDB, Inc.
A document database that stores data as flexible JSON-like records. Atlas is the hosted service
Best for App data stored as JSON-like documents, plus search, geospatial and time series queriesYou give up Free cluster: 512 MB storage, up to 100 operations per second, and no backups
Not scored yetFree - 8ElasticsearchElastic
Search engine that does keyword and vector search together; fits teams already running Elastic.
Best for Full-text and semantic search, log and metrics analysis, security analytics, vector searchYou give up Some features are paid; the AGPLv3 option covers only the free parts of the code
Not scored yetFree - 9Oracle AI Database FreeOracle
A no-cost edition of Oracle's relational database, which Oracle calls a starting point for developers
Best for Learning, testing, proofs of concept and private sandboxes (Oracle's stated uses)You give up Free edition caps at 2 CPU threads, 2 GB of RAM and 12 GB of user data
Not scored yetFree - 10Amazon DynamoDBAmazon
Amazon's hosted NoSQL database for key-value and document data, with no servers to manage
Best for Apps needing steady speed at any scale: game state, leaderboards, orders, watchlistsYou give up Free tier is 25 GB with 25 read and 25 write units per Region; use beyond that is billed
Not scored yetFree - 11SupabaseSupabase
A hosted Postgres database bundled with sign-in, file storage, live updates and server functions
Best for Building an app backend on Postgres with built-in auth, file storage and realtime updatesYou give up Free: 500 MB database, 2 active projects, and projects pause after 1 week idle
Not scored yetFree - 12BigQueryGoogle
Google's hosted data warehouse for running SQL over very large datasets without managing servers
Best for Analytics, data warehousing, business reports and machine learning with SQLYou give up Free each month: 10 GiB stored and 1 TiB queried; then $6.25 per TiB scanned
Not scored yetFree - 13DuckDBDuckDB Foundation
A small analytics database that runs inside your program, built for fast queries over whole tables
Best for Analytical queries such as totals and summaries over large tables, run inside your appYou give up Only one process can write to a database file at a time
Not scored yetFree - 14ValkeyLinux Foundation (Valkey project)
An open-source in-memory key-value store backed by the Linux Foundation, which grew out of Redis code
Best for Caching, message queues, and as a primary key-value databaseYou give up Snapshot-only saving can lose several minutes of writes after a crash, per Valkey docs
Not scored yetFree - 15Cloud FirestoreGoogle
Google's hosted document database for mobile and web apps, part of Firebase
Best for Mobile and web apps with rich data that need queries, scale and high availabilityYou give up Free Spark plan: 1 GiB stored, 50,000 reads and 20,000 writes per day
Not scored yetFree - 16H2 Database EngineH2 Group
A small Java SQL database (about 2.5 MB) that runs embedded, as a server, or fully in memory
Best for Java apps that need an embedded or in-memory SQL database, such as for testsYou give up FAQ says after a power failure the database sometimes could not be opened
Not scored yetFree - 17Azure Cosmos DBMicrosoft Azure
Microsoft's hosted NoSQL database on Azure, spread across regions
Best for Hosted NoSQL app data on Azure with provisioned or autoscale throughputYou give up Free: 1,000 request units a second and 25 GB; one free account per subscription
Not scored yetFree - 18Firebase Realtime DatabaseGoogle
Firebase's original hosted JSON database that syncs changes to connected apps in real time
Best for Apps with simple data that need low-latency live sync, such as presence or chatYou give up Free: 1 GB stored and 100 connections; queries can sort or filter on a property, not both
Not scored yetFree - 19InfluxDB 3 CoreInfluxData
A database built for time series data, such as sensor readings and metrics that arrive over time
Best for Collecting time series data at high speed and querying recent data quicklyYou give up Core is single node and tuned for recent data; long-range history needs Enterprise
Not scored yetFree
| # | Name | Score | What placed it | Price | Best for | You give up |
|---|---|---|---|---|---|---|
| 1 | PostgreSQLPostgreSQL Global Development Group · Open source | Not scored | Used by about 58% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'PostgreSQL' 57.9% (6,984 of 12,061). not scored: no recent independent test Report a mistake | Free, open source (PostgreSQL License) | Apps that need reliable SQL storage, JSON documents, and maps data via the PostGIS add-on | Self-hosted: you run, back up and update the server yourself |
| 2 | SQLiteSQLite developers (Hwaci) · Open source | Not scored | Used by about 42% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'SQLite' 42.1% (5,083 of 12,061). not scored: no recent independent test Report a mistake | Free, public domain (no licence needed) | App file formats, phones and devices, small sites, data analysis, testing and teaching SQL | Only one writer at a time per database file; not meant for many clients over a network |
| 3 | MySQLOracle · Open source | Not scored | Used by about 35% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'MySQL' 35.1% (4,235 of 12,061). not scored: no recent independent test Report a mistake | Free, open source (GPL, Community Edition) | Relational data for apps, with replication and clustering in the free Community Edition | GPLv2: shipping it inside closed-source software you sell needs a paid Oracle licence |
| 4 | RedisRedis Ltd. · Open source | Not scored | Used by about 28% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'Redis' 28.3% (3,414 of 12,061). not scored: no recent independent test Report a mistake | Free to self-host (Redis 8+: AGPLv3, RSALv2 or SSPLv1) | Caching, message brokering, streams, and document or vector data held in memory | Open licence is AGPLv3: offer a changed version as a service and you must share the code |
| 5 | Microsoft SQL ServerMicrosoft · Closed | Not scored | Used by about 27% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'Microsoft SQL Server' 27.1% (3,270 of 12,061). not scored: no recent independent test Report a mistake | Free Express edition: 50 GB per database, up to 4 cores; paid editions for more | Learning, and desktop or small server apps (Microsoft's stated fit for Express) | Express caps each database at 50 GB and uses at most 4 cores and 1,410 MB of buffer memory |
| 6 | MariaDBMariaDB Foundation and MariaDB plc · Open source | Not scored | Used by about 20% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'MariaDB' 20.3% (2,446 of 12,061). not scored: no recent independent test Report a mistake | Free, open source (GPLv2) | Relational data for apps, including apps written for MySQL | GPLv2: an app you ship that needs the server may take on GPL duties; client libs are LGPL |
| 7 | MongoDBMongoDB, Inc. · Closed | Not scored | Used by about 19% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'MongoDB' 19.0% (2,297 of 12,061). not scored: no recent independent test Report a mistake | Free tier (Atlas M0): 512 MB storage, shared CPU, no backups; Flex from $8/mo | App data stored as JSON-like documents, plus search, geospatial and time series queries | Free cluster: 512 MB storage, up to 100 operations per second, and no backups |
| 8 | ElasticsearchElastic · Open source | Not scored | Used by about 15% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'Elasticsearch' 14.8% (1,784 of 12,061). not scored: no recent independent test Report a mistake | Free to self-host (AGPLv3, SSPL or Elastic License 2.0); some features paid | Full-text and semantic search, log and metrics analysis, security analytics, vector search | Some features are paid; the AGPLv3 option covers only the free parts of the code |
| 9 | Oracle AI Database FreeOracle · Closed | Not scored | Used by about 9% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'Oracle' 9.4% (1,135 of 12,061). not scored: no recent independent test Report a mistake | Free edition: up to 2 CPU threads, 2 GB RAM, 12 GB user data | Learning, testing, proofs of concept and private sandboxes (Oracle's stated uses) | Free edition caps at 2 CPU threads, 2 GB of RAM and 12 GB of user data |
| 10 | Amazon DynamoDBAmazon · Closed | Not scored | Used by about 9% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'Dynamodb' 9.3% (1,116 of 12,061). not scored: no recent independent test Report a mistake | Free tier: 25 GB storage, 25 read and 25 write units per month; pay as you go after | Apps needing steady speed at any scale: game state, leaderboards, orders, watchlists | Free tier is 25 GB with 25 read and 25 write units per Region; use beyond that is billed |
| 11 | SupabaseSupabase · Closed | Not scored | Used by about 8% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'Supabase' 7.7% (933 of 12,061). not scored: no recent independent test Report a mistake | Free tier: 500 MB database, 2 active projects, pauses after 1 week idle; Pro from $25/mo | Building an app backend on Postgres with built-in auth, file storage and realtime updates | Free: 500 MB database, 2 active projects, and projects pause after 1 week idle |
| 12 | BigQueryGoogle · Closed | Not scored | Used by about 7% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'BigQuery' 6.7% (809 of 12,061). not scored: no recent independent test Report a mistake | Free tier: 10 GiB storage and 1 TiB of queries per month; then $6.25 per TiB | Analytics, data warehousing, business reports and machine learning with SQL | Free each month: 10 GiB stored and 1 TiB queried; then $6.25 per TiB scanned |
| 13 | DuckDBDuckDB Foundation · Open source | Not scored | Used by about 6% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'DuckDB' 5.7% (690 of 12,061). not scored: no recent independent test Report a mistake | Free, open source (MIT License) | Analytical queries such as totals and summaries over large tables, run inside your app | Only one process can write to a database file at a time |
| 14 | ValkeyLinux Foundation (Valkey project) · Open source | Not scored | Used by about 5% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'Valkey' 5.0% (603 of 12,061). not scored: no recent independent test Report a mistake | Free, open source (BSD) | Caching, message queues, and as a primary key-value database | Snapshot-only saving can lose several minutes of writes after a crash, per Valkey docs |
| 15 | Cloud FirestoreGoogle · Closed | Not scored | Used by about 5% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'Cloud Firestore' 4.8% (582 of 12,061). not scored: no recent independent test Report a mistake | Free tier (Spark): 1 GiB stored, 50,000 reads and 20,000 writes per day | Mobile and web apps with rich data that need queries, scale and high availability | Free Spark plan: 1 GiB stored, 50,000 reads and 20,000 writes per day |
| 16 | H2 Database EngineH2 Group · Open source | Not scored | Used by about 5% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'H2' 4.7% (564 of 12,061). not scored: no recent independent test Report a mistake | Free, open source (MPL 2.0 or EPL 1.0) | Java apps that need an embedded or in-memory SQL database, such as for tests | FAQ says after a power failure the database sometimes could not be opened |
| 17 | Azure Cosmos DBMicrosoft Azure · Closed | Not scored | Used by about 4% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'Cosmos DB' 4.3% (513 of 12,061). not scored: no recent independent test Report a mistake | Free tier: 1000 RU/s and 25 GB for the life of the account; billed beyond | Hosted NoSQL app data on Azure with provisioned or autoscale throughput | Free: 1,000 request units a second and 25 GB; one free account per subscription |
| 18 | Firebase Realtime DatabaseGoogle · Closed | Not scored | Used by about 4% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'Firebase Realtime Database' 4.2% (504 of 12,061). not scored: no recent independent test Report a mistake | Free tier (Spark): 1 GB stored, 10 GB downloaded per month, 100 connections | Apps with simple data that need low-latency live sync, such as presence or chat | Free: 1 GB stored and 100 connections; queries can sort or filter on a property, not both |
| 19 | InfluxDB 3 CoreInfluxData · Open source | Not scored | Used by about 4% of developers asked (Stack Overflow survey 2026)NotesTheir figure: SO 2026 'InfluxDB' 3.6% (432 of 12,061). not scored: no recent independent test Report a mistake | Free, open source (MIT and Apache 2.0, InfluxDB 3 Core) | Collecting time series data at high speed and querying recent data quickly | Core is single node and tuned for recent data; long-range history needs Enterprise |
Nothing matches all of that. , or try everything.
How we ranked this
Order. By share of developers using it in the Stack Overflow 2026 survey (all respondents). Only databases with a free option are listed; vector databases have their own list. Contains information from the Stack Overflow Developer Survey 2026, which is made available under the Open Database License (ODbL).
How we score this list. Our checklist. No recent independent test compares these databases, so every row is Not scored. The full rules are on How we score. Open "How it was scored" on any row to see the working.
What we did not do. We did not run any of these ourselves. Every number comes from the public source linked on its row, checked on 19 Oct 2026.
Spot a mistake? A wrong rank, price or link: tell us and we will check it against the source. Corrections are dated in News.
Reviews are drafted with help from AI models, including Anthropic's Claude. Model scores come only from outside leaderboards and independent evaluations, by a written rule.