MongoDB vs Supabase for Solo Developers

Quick Comparison

MongoDB Overview

MongoDB is the leading NoSQL database. It stores data as flexible JSON-like documents, which means you do not need to define a rigid schema before storing data. For rapid prototyping and applications where data structures evolve frequently, this flexibility is useful.

MongoDB Atlas provides a managed cloud service with a free tier (512 MB storage on a shared cluster). The Atlas dashboard gives you monitoring, backups, and search capabilities. For solo developers who want a cloud database without managing servers, Atlas works well.

The document model is genuinely powerful for certain use cases. Content management systems, product catalogs with varying attributes, event logs, and IoT data all fit naturally into documents. But for most web applications with users, orders, products, and relationships between them, the document model introduces complexity that relational databases handle more cleanly.

Supabase Overview

Supabase is not just a database. It is a full backend platform built on PostgreSQL. You get a Postgres database, authentication, file storage, edge functions, real-time subscriptions, and auto-generated REST and GraphQL APIs. All from one dashboard, one project, one bill.

The solo developer rating of 10/10 is not an exaggeration. Supabase gives you everything you need to build a full-stack application without writing backend code. Create a table, and you immediately have CRUD API endpoints. Enable row-level security, and your data is protected at the database level. Need auth? Built in. Need file uploads? Built in. Need real-time? Built in.

The free tier is generous: two projects, 500 MB database, 1 GB file storage, 50,000 monthly active users for auth. That covers most side projects and early-stage products.

Key Differences

Database vs platform. This is the fundamental difference. MongoDB gives you a database. Supabase gives you a database plus auth, storage, real-time, edge functions, and auto-generated APIs. As a solo developer, every feature Supabase bundles is a feature you do not need to build or integrate yourself. MongoDB requires you to add authentication (Auth0, Clerk), file storage (S3, Cloudflare R2), and real-time (Socket.io) separately.

SQL vs document queries. Supabase gives you full PostgreSQL, which means SQL with JOINs, CTEs, window functions, JSONB, full-text search, and extensions. MongoDB uses its own query language and aggregation pipelines. For complex queries involving multiple entities, SQL is more expressive. MongoDB's aggregation pipeline can do similar things but with more verbose syntax.

Schema flexibility vs integrity. MongoDB's schema-free approach means any document can have any shape. Supabase (PostgreSQL) enforces schemas with types, constraints, and foreign keys. For solo developers, the PostgreSQL approach catches data bugs at the database level. MongoDB's flexibility feels fast initially but creates data quality issues as the application grows.

Real-time capabilities. Both support real-time data. Supabase has real-time subscriptions built into the platform. You subscribe to table changes and get updates over WebSockets. MongoDB has Change Streams for real-time data, but you need to build the WebSocket infrastructure yourself or use MongoDB Realm (now Atlas App Services).

Row-level security. Supabase's row-level security lets you define access control policies directly in the database. Users can only see and modify their own data, enforced at the PostgreSQL level. MongoDB has document-level security through MongoDB Realm, but the setup is more complex and less integrated.

Cost for what you get. MongoDB Atlas free tier gives you a database. Supabase free tier gives you a database, auth, storage, and APIs. At $25/month (Supabase Pro), you get a production-ready backend. With MongoDB, reaching feature parity with Supabase means paying for multiple services.

When to Choose MongoDB

• Your data is genuinely document-oriented with nested, varying structures
• You need MongoDB-specific features like Atlas Search or time-series collections
• You are already invested in the MongoDB ecosystem (Mongoose, Realm)
• Your application does not need auth, storage, or real-time from the database layer
• You prefer the MongoDB query language over SQL

When to Choose Supabase

• You want a complete backend platform, not just a database
• Built-in authentication saves you from integrating a separate auth service
• Real-time subscriptions are part of your application
• You prefer SQL and relational data modeling
• You want the fastest path from idea to deployed product

The Verdict

Supabase wins decisively for solo developers. The 10/10 vs 7/10 rating tells the story. Supabase gives you everything MongoDB gives you (data storage, cloud hosting, free tier) plus authentication, file storage, real-time, auto-generated APIs, and row-level security. All on top of PostgreSQL, which has stronger querying capabilities than MongoDB for most use cases.

MongoDB is a good database for specific use cases. But when you are a solo developer building a web application, Supabase replaces not just your database but half your backend. That is a massive time and cost savings. Pick Supabase unless you have a specific, compelling reason to use MongoDB.