Is MongoDB Atlas free? What it actually costs in 2026

What the free tier actually includes

• —512 MB of storage
• —Shared vCPU and RAM
• —One free cluster per project

Where the wall is

512 MB, and shared compute. Any real dataset or any latency requirement moves you to Flex or a dedicated tier, priced by the hour.

After that: Flex from $0.011 an hour (about $8 a month at the base tier, up to $30); Dedicated M10 from $0.08 an hour, about $56.94 a month, with 2 vCPU, 2 GB RAM and 10–128 GB of storage.

Can you self-host MongoDB Atlas? Yes

MongoDB Community Server runs anywhere under the SSPL, and FerretDB puts a MongoDB-compatible API on top of PostgreSQL — both compared here.

What it actually takes to run one yourself

Real RAM against the documented minimum, monthly cost, setup time, and the one thing that catches people out.

When paying is still the right call

Stay if you use Atlas Search or Vector Search — replacing them means standing up OpenSearch or a vector database and wiring it yourself, which usually costs more than the cluster. Stay if nobody on the team wants to own a replica set, because operating MongoDB properly across availability zones is genuinely demanding and doing it badly is worse than paying. Stay if you need multi-cloud or specific compliance attestations. And stay if you are on the free M0 tier, which covers a great many real projects.

What you are locked into

Moderate. The wire protocol and query language are MongoDB's, so application code is written against them — but that is precisely what FerretDB re-implements, which makes it the cheapest exit in the category. Data exports with `mongodump`. What genuinely binds you is Atlas-specific functionality: Atlas Search, Atlas Vector Search, Triggers and Data Federation have no equivalent in self-hosted MongoDB, let alone elsewhere. Teams that stick to plain queries move easily; teams that adopted Atlas Search have rebuilt search ahead of them.

If you would rather not pay: PostgreSQL