Published February 27, 2026 · 15 min read
Every application needs a database, and in 2026 you do not need to spend money to get a good one. The major cloud database providers offer free tiers that are generous enough to run production applications, handle thousands of users, and store gigabytes of data without paying a dollar.
This guide compares the five best free database platforms: Supabase, PlanetScale, Firebase, MongoDB Atlas, and Neon. We cover both SQL (relational) and NoSQL (document) options, with detailed free tier limits, features, and recommendations for different use cases.
Here is a side-by-side comparison of what each platform offers at no cost as of February 2026.
| Feature | Supabase | PlanetScale | Firebase | MongoDB Atlas | Neon |
|---|---|---|---|---|---|
| Database Type | PostgreSQL | MySQL | NoSQL (Firestore/RTDB) | NoSQL (Document) | PostgreSQL |
| Free Storage | 500 MB | 5 GB | 1 GB (Firestore) | 512 MB | 512 MB |
| Free Reads | Unlimited | 1B row reads/mo | 50K reads/day | Unlimited | Unlimited |
| Free Writes | Unlimited | 10M row writes/mo | 20K writes/day | Unlimited | Unlimited |
| Compute | Shared CPU | Serverless | Serverless | Shared M0 (512 MB RAM) | 0.25 vCPU |
| Branching | No (free) | Yes (1 branch) | No | No | Yes (10 branches) |
| Auth Built-in | Yes (50K MAUs) | No | Yes (unlimited) | No | No |
| File Storage | Yes (1 GB) | No | Yes (5 GB) | No | No |
| Realtime | Yes | No | Yes | Change streams | No |
| Pausing Policy | Paused after 7 days inactive | Sleep after 7 days | No pausing | No pausing | Scales to zero |
Supabase is often described as "the open-source Firebase alternative," but it is built on PostgreSQL rather than a NoSQL database. This means you get the full power of SQL, including joins, transactions, foreign keys, and views, combined with real-time subscriptions, built-in authentication, file storage, and auto-generated REST and GraphQL APIs.
Full-stack web applications that need a relational database, user authentication, and file uploads. Supabase replaces your database, auth provider, and file storage with a single platform. A typical SaaS MVP with user accounts, data tables, and file uploads fits entirely within the free tier.
Supabase's biggest advantage is the all-in-one package. You get PostgreSQL, authentication (email, social OAuth, magic links), file storage with CDN, edge functions, and real-time data sync. For solo developers and startups, this eliminates the need to stitch together five different services.
Free projects are paused after 7 days of inactivity. This is fine for active projects but problematic for side projects you check on monthly. The 500 MB storage limit is adequate for most applications but fills up quickly if you store large JSON documents or blobs in the database (use file storage for those).
PlanetScale brings the database technology behind YouTube (Vitess) to developers as a managed serverless MySQL platform. The free tier is notably generous with 5 GB of storage, making it one of the largest free database offerings available.
Applications that need MySQL compatibility, large storage, or database branching for safe schema migrations. PlanetScale's branching workflow lets you test schema changes on a development branch before merging to production, similar to Git branching for code. This is unique among free database offerings.
The 5 GB storage limit is the most generous on this list. The branching workflow is a genuine innovation that makes schema migrations safer. Serverless scaling means you do not worry about provisioning compute. PlanetScale also supports connection pooling out of the box, which is essential for serverless application architectures.
PlanetScale does not support foreign key constraints at the database level (a limitation of Vitess). You enforce referential integrity at the application level instead. This is a deal-breaker for some developers and a non-issue for others. There is also no built-in authentication or file storage, so you need separate services for those.
Firebase is Google's application development platform. It offers two database options: the original Realtime Database (a JSON tree) and Firestore (a document-collection database). Both have free tiers, and Firebase bundles authentication, file storage, hosting, and cloud functions into its free Spark plan.
Real-time applications like chat apps, live dashboards, collaborative tools, and mobile apps. Firebase's real-time data synchronization is unmatched. When data changes in Firestore, every connected client receives the update instantly without polling. Combined with unlimited free authentication and generous hosting, Firebase is the most complete free platform for client-heavy applications.
Firebase is the most mature platform on this list with the broadest ecosystem. Google SDKs for Android, iOS, and web are first-class. Real-time sync is built into the SDK, not bolted on. The authentication system supports every major provider and is genuinely unlimited on the free tier. For mobile developers especially, Firebase remains the default choice.
Firestore is a NoSQL document database. If your data is highly relational (many-to-many relationships, complex joins, aggregate queries), you will fight the data model. The daily read/write limits (50K reads, 20K writes) can be restrictive for applications with heavy read patterns. Costs can spike unpredictably on the paid plan if you are not careful with query design.
MongoDB Atlas is the managed cloud version of MongoDB, the most popular NoSQL document database. The free M0 cluster provides 512 MB of storage with no time limit and no credit card required. It is the easiest way to get a production MongoDB instance running in minutes.
Applications with flexible, evolving data schemas. MongoDB stores data as JSON-like documents, so you do not need to define a rigid table schema before writing data. This is ideal for prototyping, content management systems, product catalogs with varying attributes, and any application where the data structure changes frequently.
MongoDB's document model is intuitive for JavaScript developers because documents look like JSON objects. The free tier never pauses or expires, unlike Supabase and PlanetScale. Atlas Search provides built-in full-text search without needing a separate Elasticsearch instance. The aggregation pipeline is powerful for complex data transformations.
512 MB is the smallest free storage on this list. The shared cluster can have variable performance during peak times. There is no built-in authentication, file storage, or real-time sync (you need change streams for near-real-time, which is different from Firebase's instant sync). For truly relational data, PostgreSQL (Supabase or Neon) is a better fit.
Neon is a newer entrant that brings serverless architecture to PostgreSQL. The standout feature is database branching: you can create instant copies of your database for development, testing, or previewing schema changes. Neon also scales to zero, meaning you are not charged for compute when your database is idle.
Developers who want PostgreSQL with modern developer experience features. Neon's branching is perfect for preview deployments (every PR gets its own database branch), CI/CD pipelines that need isolated test databases, and safe schema migrations. If you use Vercel or similar platforms with preview deployments, Neon integrates directly.
Scale-to-zero means the free tier never penalizes you for inactivity, unlike Supabase's 7-day pause. Branching is a game-changer for development workflows. Point-in-time restore provides safety against accidental data loss. Full PostgreSQL compatibility means any PostgreSQL tool, ORM, or library works without modification.
Neon is database-only. There is no built-in authentication, file storage, or edge functions. You need to pair it with separate services (Clerk for auth, Cloudflare R2 for storage, etc.). The 0.25 vCPU compute is sufficient for development and low-traffic production but will feel limited under heavy concurrent load.
Use this decision framework to pick the right free database for your project.
| If You Need... | Choose | Reason |
|---|---|---|
| All-in-one (DB + Auth + Storage) | Supabase or Firebase | Both bundle multiple services free |
| Most free storage | PlanetScale (5 GB) | 10x more than most competitors |
| Real-time data sync | Firebase | Best-in-class real-time SDK |
| Flexible document schema | MongoDB Atlas | JSON documents, no rigid schema |
| Database branching | Neon or PlanetScale | Git-like workflow for schema changes |
| Full SQL with joins | Supabase or Neon | PostgreSQL with full SQL support |
| Never-pausing free tier | MongoDB Atlas or Neon | No inactivity penalties |
| Mobile app backend | Firebase | First-class mobile SDKs |
There is no rule saying you must use one database. Many production applications use Firebase for authentication and real-time features, Supabase or Neon for relational data, and MongoDB for flexible document storage. Each free tier is independent, giving you significant combined capacity at zero cost.
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Get the Free SQL FormatterYes, for small to medium-scale applications. Many startups run their initial production workloads entirely on free tiers. The key limitations are storage (512 MB to 5 GB), compute (shared or minimal), and in some cases daily operation limits (Firebase). If your application has fewer than 10,000 daily active users and your database is under 1 GB, free tiers handle production traffic without issues. Monitor your usage and plan to upgrade when you approach limits.
Choose SQL (PostgreSQL via Supabase/Neon, or MySQL via PlanetScale) if your data has clear relationships between entities (users have orders, orders have items, items belong to categories). Choose NoSQL (Firebase Firestore or MongoDB Atlas) if your data is hierarchical, has varying structure, or if you need real-time synchronization. When in doubt, start with PostgreSQL. SQL databases can handle document-style data via JSON columns, but NoSQL databases cannot easily handle relational queries.
It depends on the platform. Supabase pauses your project after 7 days of inactivity and requires an upgrade if you exceed storage. PlanetScale throttles read/write performance. Firebase starts rejecting operations once daily limits are reached (hard limit). MongoDB Atlas prevents new writes when storage is full. Neon scales to zero but does not cut you off. None of the platforms charge you automatically without consent. You always have the option to upgrade or optimize your usage.