MongoDB Atlas
Managed MongoDB in the cloud — document database with flexible schemas and a massive ecosystem
MongoDB Atlas is the managed cloud version of MongoDB, the most popular document database. You get a free shared cluster with 512 MB of storage that stays running 24/7 — no pausing for inactivity like some competitors. Documents store as JSON-like objects, so your data structure can evolve without formal migrations. This makes it fast to prototype with.
The tradeoff is well-documented: document databases trade query flexibility for schema flexibility. As your app grows, you may find yourself duplicating data across collections or writing complex aggregation pipelines that would be simple JOINs in SQL. For solo founders, MongoDB works best when your data is naturally document-shaped (CMS content, user profiles, event logs). If your data has lots of relationships, Postgres on Supabase or Neon will save you headaches down the road.
What's good
- Free tier with 512 MB storage that never pauses or sleeps
- Flexible document model — no migrations needed when your schema changes
- Largest NoSQL ecosystem — drivers for every language, huge community, extensive docs
Watch out for
- Document databases encourage denormalization that becomes messy as your app grows
- Dedicated clusters start at $57/mo — the jump from free to paid is steep
- Aggregation pipeline syntax has a steep learning curve compared to SQL
Alternatives
Supabase
Postgres database with built-in auth, storage, and real-time — the open-source Firebase alternative
Neon
Serverless Postgres that scales to zero — you only pay when your database is actually being used
Xata
Serverless database with full-text search, file attachments, and a spreadsheet-like UI built in