MongoDB Alternatives 2026: 5 Free Options
MongoDB alternatives: Supabase, Firebase, Appwrite, Apache CouchDB and 1 more. Prices and licenses checked October 25, 2026.
•3 min read•Databases & Database Tools
Verdict:Leave MongoDB when your data is relational or your team wants SQL, not when you simply need a managed document store. MongoDB Atlas has a free M0 tier with 512 MB of storage, and paid Flex clusters start at about $8 a month, billed hourly. PostgreSQL is the most common replacement. It runs on your own server and handles JSON columns for document-like data, but the schema must be designed up front. Supabase gives you Postgres with hosted auth and APIs, and its free plan is a practical start for a small app. Firebase Firestore is the nearest document-model match, with a free Spark tier and pay-as-you-go pricing, but its query language and data model differ, so queries must be rewritten. Apache CouchDB is closer in spirit: JSON documents, an HTTP API, an Apache 2.0 licence and self-hosting only. Appwrite bundles a database with auth, storage and functions as an open-source backend. Pick PostgreSQL for long-term data integrity, CouchDB for replication-heavy work, and Supabase when you want a hosted Postgres. The trade-off is migration cost: every query and aggregation pipeline has to be rewritten. Export one collection and test the new schema on it before moving production data.
Quick comparison
| Tool | Price | Platforms | Best for | Tested |
|---|---|---|---|---|
| Supabase | Free (Free plan: 50,000 monthly active users for Auth, 500 MB database, 2 active projects); paid from $25 per month (Pro, 100,000 MAU) | Web, Self-hosted | Relational data with a hosted backend | Docs only |
| Firebase | Free (Spark no-cost plan: Firestore 1 GiB stored, Auth 50K monthly active users, Hosting 10 GB) | Web, Cloud | Document data with real-time apps | Docs only |
| Appwrite | Free (Free plan: 2 projects per organization, 75K monthly active users, 5 GB bandwidth, 2 GB storage); paid from $25 per month, Pro plan | Web, Self-hosted, Cloud | Self-hosted backend with a database | Docs only |
| Apache CouchDB | Free (Free to self-host under Apache 2.0; you pay for your own server) | Self-hosted server | Replication-heavy document storage | Docs only |
| PostgreSQL | Free (Free to use; you pay for your own server) | Self-hosted server | Long-term data integrity and SQL | Docs only |
| Amazon DynamoDB | See pricing page | Cloud | Database | Docs only |
Independent comparison. Paid placements are labelled separately; editorial links earn no affiliate commissions. Learn more.
Good fit if
- Your data is relational or you want SQL (PostgreSQL is the pick)
- You want hosted Postgres with auth and APIs (Supabase is the pick)
- You build real-time apps on documents (Firebase is the pick)
- You want a self-hosted backend in one stack (Appwrite is the pick)
Not ideal if
- You rely on MongoDB features or integrations that these tools do not replicate
MongoDB today: Free (M0 cluster free forever with 512 MB storage); paid from $8 per month, Flex cluster base tier billed hourly (about $0.011 per hour, assuming 30 days of use) (MongoDB pricing, checked 2026-10-23).
Why people look for MongoDB alternatives
MongoDB Atlas's free M0 cluster has 512 MB of storage and about 100 operations per second. Flex starts at $0.011 per hour with a $30 monthly cap, and covers up to 500 operations per second. Past that you move to Dedicated clusters, where M10 starts at $0.08 per hour, about $56.94 per month. Backups are billed by snapshot storage and are not available on the free tier, data leaving Dedicated clusters is charged, and Stream Processing and dedicated Search nodes are paid add-ons.
Supabase
Compared with MongoDB: Free plan offers Postgres with hosted APIs and auth. Against MongoDB you gain SQL and row-level security, but you lose schemaless JSON documents and the aggregation pipeline.
Price: Free (Free plan: 50,000 monthly active users for Auth, 500 MB database, 2 active projects); paid from $25 per month (Pro, 100,000 MAU) (Supabase pricing, checked 2026-10-22).
Platforms and license: Web, Self-hosted. Proprietary.
Best for: Relational data with a hosted backend.
Worth knowing: Free projects pause after 1 week of inactivity.
Firebase
Compared with MongoDB: Firestore is a document database with a free Spark tier and pay-as-you-go pricing. Against MongoDB you lose its query language and easy self-hosting, and queries must be rewritten.
Price: Free (Spark no-cost plan: Firestore 1 GiB stored, Auth 50K monthly active users, Hosting 10 GB) (Firebase pricing, checked 2026-10-22).
Platforms and license: Web, Cloud. Proprietary.
Best for: Document data with real-time apps.
Worth knowing: Blaze is pay as you go with no flat monthly fee; eligible users may get $300 free credit. Firestore is a document database, not Postgres.
Appwrite
Compared with MongoDB: Open-source backend with a free plan and a paid tier from $25 per the pricing page. Against MongoDB you get auth, storage and functions in one stack, but it is a full backend, not a database alone.
Price: Free (Free plan: 2 projects per organization, 75K monthly active users, 5 GB bandwidth, 2 GB storage); paid from $25 per month, Pro plan (Appwrite pricing, checked 2026-10-22).
Platforms and license: Web, Self-hosted, Cloud. BSD-3-Clause (open source).
Project activity: 57.8k GitHub stars · latest release 2.6.2 (Oct 24, 2026) · last commit Oct 27, 2026
Best for: Self-hosted backend with a database.
Apache CouchDB
Compared with MongoDB: Apache 2.0 licensed document database with a JSON model and HTTP API. Against MongoDB you lose the aggregation pipeline and hosted Atlas, but you pay no licence fee and host it yourself.
Price: Free (Free to self-host under Apache 2.0; you pay for your own server) (Apache CouchDB pricing, checked 2026-10-22).
Platforms and license: Self-hosted server. Apache License 2.0 (open source).
Project activity: 7k GitHub stars · last commit Oct 27, 2026
Best for: Replication-heavy document storage.
Worth knowing: The project site lists no hosted paid tier.
PostgreSQL
Compared with MongoDB: Open-source relational database with JSON column support, so it covers many document use cases. Against MongoDB you must design a schema up front, and you run or rent the server yourself.
Price: Free (Free to use; you pay for your own server) (PostgreSQL pricing, checked 2026-10-23).
Platforms and license: Self-hosted server. PostgreSQL License (open source).
Best for: Long-term data integrity and SQL.
Other popular options (paid)
Amazon DynamoDB
Compared with MongoDB: Fully managed AWS service billed per request: on-demand lists $0.625 per million writes and $0.125 per million reads, with 25 GB of storage in the free tier. Costs follow traffic rather than an hourly cluster size.
Price: See pricing page (Amazon DynamoDB pricing, checked 2026-10-25).
Which one to pick
- Your data is relational or you want SQL: PostgreSQL
- You want hosted Postgres with auth and APIs: Supabase
- You build real-time apps on documents: Firebase
- You want a self-hosted backend in one stack: Appwrite
Limits of this review
Docs-only for Supabase, Firebase, Appwrite, Apache CouchDB, PostgreSQL: we did not install or run them, so feature claims come from vendor pages and we did not test import from MongoDB. Vendor prices and free limits change; confirm on the linked pricing page before you buy or migrate.
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Kevin Fan
Kevin Fan is a SaaS founder. He runs Free Instead Of, which tracks free and open-source alternatives to paid software and checks each price and free-plan limit against the vendor's own pages.
Methodology
Based on official pricing and product pages checked between 2026-10-22 and 2026-10-25: MongoDB, Supabase, Firebase, Appwrite, Apache CouchDB, PostgreSQL, Amazon DynamoDB. Prices, free limits and licenses are the figures shown on those pages on those dates. No tool on this page was installed or run. No accounts were created.