Apache CouchDB vs FerretDB
Both are alternatives to MongoDB Atlas. Here's how they stack up — verified facts, no spin.
Also searched as FerretDB vs Apache CouchDB — same comparison, one verdict.
Apache CouchDB and FerretDB are closely matched on ownership (96 vs 95) — this one comes down to pricing and to which trade-offs below you can live with.
Apache CouchDB
Apache-2.0 documents, built around offline sync.
CouchDB is a document database under the Apache Software Foundation with a distinguishing feature nothing else here matches: replication designed for intermittent connectivity, so devices can work offline and reconcile later. If you are building something that must function on a phone in a field with no signal, CouchDB with PouchDB in the client solves a problem MongoDB does not attempt. Apache-2.0 with foundation governance, so the licence question is settled permanently. It is slower and less fashionable than the alternatives, and for its particular job it has no real competitor.
FerretDB
MongoDB's wire protocol, speaking to Postgres underneath.
FerretDB 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.
Side by side
10 points of comparison, every one read from a verified field. Green marks the side that wins a row outright. A dash means we do not hold that fact — never that it is zero.
| Apache CouchDB | FerretDB | |
|---|---|---|
| Sovereignty ScoreOur transparent 0–100 composite for data ownership and exit cost. | 96 | 95 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first data | Yes | Yes |
| License | Apache-2.0 | Apache-2.0 |
| Pricing | Free and open source. Managed hosting available from several providers. | Free and open source. You run it alongside your own Postgres. |
| RAM to run it wellThe figure that actually matters, not the vendor's minimum. | 4 GB | — |
| Realistic running costWhat the box costs each month if you run it yourself. | $18–35/mo, against MongoDB Atlas pricing | — |
| Setup timeHonest first-install estimate, not the marketing quickstart. | 1 hour | — |
| Ongoing maintenanceThe part nobody budgets for. | Moderate. Compaction is the recurring job and it is not optional. | — |
Apache CouchDB edges it on the Sovereignty Score, but the right pick depends on the trade-offs below.
Weighing both against staying on MongoDB Atlas? Is MongoDB Atlas free? What it actually costs →
Apache CouchDB
Strengths
- +Apache Software Foundation governance — the licence is settled
- +Best offline-first replication of any database in this comparison
- +Pairs with PouchDB for genuinely offline-capable applications
- +Simple HTTP and JSON interface with no driver required
Trade-offs
- −Slower than MongoDB or Postgres for general workloads
- −Query capability is weaker; map-reduce views take adjusting to
- −Smaller community and less momentum
- −Wrong choice unless offline sync is genuinely your problem
FerretDB
Strengths
- +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
Trade-offs
- −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
Which one fits you
The trade-offs above, turned into a decision. Find the line that describes your team.
Choose Apache CouchDB
if a lower exit cost matters more to you than any single feature, and apache Software Foundation governance — the licence is settled.
Choose FerretDB
if existing MongoDB drivers and queries keep working — minimal code change.
Neither, yet
if both carry a real cost you should weigh first — slower than MongoDB or Postgres for general workloads, and compatibility is good but not complete — test your aggregations. If either of those is a dealbreaker for your team, the shortlist is wrong rather than the choice.
What it takes to run these yourself
Real requirements and honest running costs, not the vendor quickstart.
Apache CouchDB vs FerretDB — common questions
Is Apache CouchDB a better fit than FerretDB for managed databases?
It depends on what you are optimising for, and the honest split is this: Apache CouchDB scores 96 to FerretDB's 95 on data ownership and exit cost, so it is the safer choice if you care about being able to leave. FerretDB earns its place on a different axis — existing MongoDB drivers and queries keep working — minimal code change. Neither is a wrong answer for every team; the table above is the actual comparison.
What happens if we want to switch later?
Apache CouchDB keeps its data local or in open formats, so leaving is an export rather than a negotiation. FerretDB is still self-hostable, so the files stay on your server either way — but it is not local-first by design, so check what its export produces before you rely on it.
Can I self-host Apache CouchDB or FerretDB?
Both can be self-hosted. The difference is what it costs you in time rather than whether it is possible — see the setup and maintenance rows above.
Are Apache CouchDB and FerretDB both alternatives to MongoDB Atlas?
Yes — both appear in our MongoDB Atlas comparison, which is why they are worth putting side by side. People usually arrive here already having decided to move off MongoDB Atlas and now choosing between the two replacements, which is a narrower and much easier question.
More MongoDB Atlas head-to-heads
Related alternative guides
Facts verified 2026-08-07. Licenses and pricing change — spotted something out of date? That's a correction we want.