FerretDB
MongoDB's wire protocol, speaking to Postgres underneath.
95
sovereigntyFerretDB implements the MongoDB wire protocol on top of Postgres, so an existing application keeps its drivers, its queries and its code while the data lives in an open relational database under a licence nobody will change. Apache-2.0, around 11k stars. It is the most surgical exit in this comparison: for the common case of a team using MongoDB as a straightforward document store, it is close to a drop-in. Compatibility is good rather than total — the exotic aggregation stages and MongoDB-specific features are where it stops.
OPEN SOURCEApache-2.0SELF-HOSTLOCAL-FIRST
LicenseApache-2.0
PricingFree and open source. You run it alongside your own Postgres.
Open sourceYes
Self-hostableYes
Local-first dataYes
What it does well
- +Existing MongoDB drivers and queries keep working — minimal code change
- +Apache-2.0, with data resting in Postgres
- +Sidesteps the SSPL question entirely
- +Lets you consolidate onto one database engine
Where it falls short
- −Compatibility is good but not complete — test your aggregations
- −Extra layer between application and storage
- −Younger project with a smaller community
- −Not faster than MongoDB; this is about licence and consolidation
FerretDB as an alternative to
Where FerretDB shows up in our comparisons, and how it ranked.
FerretDB head-to-head
Straight comparisons against the tools people weigh it against.