Yes, MongoDB is free in two ways: MongoDB Community Server is a free download you run yourself, and MongoDB Atlas has a Free cluster that MongoDB calls free forever, with 512 MB of storage. You pay when you need more storage or performance in Atlas, and the Community Server licence has a catch for anyone offering MongoDB as a service.
MongoDB comes up when clients build their first app or automation and a developer suggests it. The good news is you can build and test without paying anything. The detail worth knowing is what the free Atlas cluster can and can't handle, because it's built for learning and prototypes, not a busy live app.
MongoDB free options at a glance
| Option | What you get | Cost as of October 2026 | Storage |
|---|---|---|---|
| Community Server | The database you install and run yourself | Free download | Your own hardware |
| Atlas Free | MongoDB's cloud, for learning and exploring | Free forever ($0/hour) | 512 MB |
| Atlas Flex | Cloud, for development and testing with burst capacity | $0.011/hour, up to $30/month | 5 GB |
| Atlas Dedicated | Cloud, for production apps | From $0.08/hour; starts at $56.94/month | Scales up |
MongoDB Atlas free cluster limits
MongoDB's Atlas documentation lists the limits on Free clusters, and these are the ones that matter:
- Storage is capped at 0.5 GB, and the docs say that's a hard limit.
- You can deploy only one Free cluster per Atlas project.
- A maximum of 500 connections.
- A maximum of 100 databases and 500 collections in total.
- Data transfer of 10 GB in and 10 GB out per period.
- Aggregation pipelines can have a maximum of 50 stages.
- Atlas may deactivate idle Free clusters, as set out in its Terms of Service.
That idle point catches people out. If you build a test app, forget about it for a while and come back, check your cluster is still there before you demo it to anyone. The docs also say you can enable backups on Free clusters: Atlas takes a daily snapshot and keeps up to four.
Is MongoDB Community Server free for business?
You can download MongoDB Community Server free from MongoDB's site. Its licence is the Server Side Public License (SSPL), which MongoDB's FAQ says applies to Community Server versions released on or after 16 October 2018.
MongoDB says the SSPL keeps the freedoms to use, review, modify and redistribute the source code, and its extra terms are aimed at companies that run a publicly available MongoDB as a service. The FAQ also notes the SSPL is based on the GPL version 3 but hasn't been approved by the OSI. If you're simply using MongoDB inside your own app, that's the normal free use. If you plan to offer MongoDB itself as a service to others, read the SSPL FAQ carefully first.
How to start with MongoDB for free
- Decide where it'll run: on your own machine or server (Community Server) or in MongoDB's cloud (Atlas).
- For Atlas, create an account and deploy a Free cluster. MongoDB lists it at $0 an hour.
- Keep an eye on the 512 MB storage cap and the 500 connection limit as your app grows.
- Switch on Free cluster backups if your test data matters to you.
- Move to Flex or a Dedicated cluster when you need more storage, more speed or production reliability.
If you're weighing MongoDB against other databases, my list of MongoDB alternatives compares the main options, and this guide to free database software covers relational databases too.
Features you don't get on the Atlas Free cluster
MongoDB's documentation also lists features that aren't available on Free clusters, which matter once your app gets serious:
- No access to the Performance Advisor.
- No database auditing.
- No network peering connections or private endpoints.
- No server-side JavaScript, so JavaScript query operators and map-reduce are unsupported.
- No writing temporary files to disk: Atlas ignores the allowDiskUse option on Free and Flex clusters.
On the plus side, MongoDB's pricing page says Atlas includes free Basic Support, and Charts are included on all Atlas clusters. Flex clusters are billed hourly with monthly invoices and, MongoDB says, can cost between $8 and $30 for a month's usage as of October 2026.
My advice
Use the Atlas Free cluster to learn and prototype, and MongoDB Community Server if you're happy running your own database. Neither costs anything. Just don't put a live customer-facing app on the Free cluster: the 512 MB cap, 500 connections and the chance of an idle cluster being deactivated make it the wrong home for anything people depend on. When you're ready for real users, budget for Flex or Dedicated.
Frequently asked questions
Is MongoDB free?
Yes. MongoDB Community Server is a free download, and MongoDB Atlas has a Free cluster that MongoDB describes as free forever, with 512 MB of storage.
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What are the limits of the MongoDB Atlas free tier?
MongoDB's docs list 0.5 GB of storage as a hard limit, one Free cluster per project, a maximum of 500 connections, and 100 databases and 500 collections in total.
Can I use MongoDB Community Server for commercial apps?
MongoDB's SSPL keeps the freedom to use, modify and redistribute the code. Its extra terms target companies that offer MongoDB itself as a publicly available service.
How much does MongoDB Atlas cost after the free tier?
As of October 2026, Flex clusters are $0.011 an hour, up to $30 a month, and Dedicated clusters start at $56.94 a month.
Can I back up a free MongoDB Atlas cluster?
Yes. MongoDB's docs say you can enable backups on Free clusters, and Atlas takes a daily snapshot and keeps up to four.
How many free MongoDB Atlas clusters are allowed?
MongoDB's docs say you can deploy one Free cluster per Atlas project, though customers with sales contracts may be able to deploy more.
Is MongoDB open source?
MongoDB Community Server is licensed under the Server Side Public License (SSPL). MongoDB says the SSPL is based on the GPL version 3 but hasn't been approved by the OSI.
Does the MongoDB Atlas free tier include support?
Yes, basic support. MongoDB's pricing page says Atlas includes free Basic Support, and you can upgrade to a paid plan for faster response times.
Can MongoDB Atlas deactivate my free cluster?
Yes. MongoDB's docs say Atlas may deactivate idle Free clusters as set out in its Terms of Service, so check a test cluster is still running before you rely on it.
