Overview

CouchDB stores named documents through a RESTful HTTP API for reading and updating them. Documents can combine JSON fields and binary attachments without a fixed schema, which suits data that varies or changes over time. That flexibility shifts responsibility to the application: teams still need to define useful document structures and manage any competing revisions.

Incremental, bidirectional replication can synchronize peers after disconnections. That makes CouchDB relevant to applications that need to keep working offline, including systems syncing between servers, mobile devices, and browsers. Replicas may retain conflicting revisions, so synchronization does not remove the need for manual or automated conflict resolution.

Key features

Documents and queries

The built-in query engine supports views created with JavaScript map functions and optional reduce functions. This gives teams a way to query and summarize document data, but the view-based model is a better fit for applications designed around those views than for teams seeking a different database querying approach.

Replication and clustering

Replication works incrementally and in both directions, including when peers have spent time disconnected. PouchDB, designed for mobile devices and browsers, can replicate with CouchDB, providing a path for applications that span clients and servers. Clustering lets multiple servers or virtual machines operate as one logical database server for greater capacity and high availability, at the cost of operating the deployment yourself.

Reliability and security

CouchDB uses an append-only file design, and its documentation describes document updates as ACID and all-or-nothing. Security controls include administrator accounts, basic and cookie authentication, reader access controls, and JavaScript validation functions that can enforce custom rules on document updates. These controls offer building blocks for protecting data, while custom validation and conflict policies still require deliberate application design.

Pricing

Apache CouchDB is free open-source software under the Apache License 2.0. The Apache CouchDB plan costs 0.00 USD per free and covers self-hosting on servers or virtual machines, as a single node or cluster. There is no free trial; the software itself is free to use, with teams responsible for running it.

Platforms

CouchDB supports API-based use and is available for Linux, macOS, and Windows. It is self-hosted and web-accessible, so it suits teams choosing their own server or VM deployment rather than a hosted CouchDB service.

Who it's for

CouchDB suits developers building document-oriented applications that need flexible JSON records, binary attachments, or replication across offline-capable clients. It is also a reasonable choice when a team wants to scale a logical database across multiple servers and can take on operations and conflict handling. Teams that need a managed database or prefer not to design around revision conflicts should look elsewhere.

Pros and cons

Pros: A flexible document model accommodates changing records and attachments without a fixed schema.
Pros: Incremental bidirectional replication can reconnect disconnected peers, supporting offline-capable applications.
Pros: Clustering can increase capacity and availability across servers or VMs.
Cons: Self-hosting means teams must operate the database infrastructure themselves.
Cons: Conflicting revisions can persist across replicas, requiring application-level resolution.
Cons: Views rely on JavaScript map functions, with optional reduce functions, so teams should ensure that model fits their query needs.

Alternatives

For other options, browse Document Databases or Database Software.

RavenDB is worth comparing if its freemium offering and listed Developer and Community plans better suit your needs. Firestore is an alternative with a freemium model, trial, and daily read and write allowances on its Standard edition. MarkLogic offers a freemium option and a Developer plan for noncommercial use, as well as an Enterprise plan.

JasDB is another free database option. LiteDB is free for commercial and noncommercial use. Oracle Autonomous AI Lakehouse offers an always-free option subject to capacity limits. Couchbase Capella has a free 1-node, 8 GB plan and paid plans. Percona Server for MongoDB is a free, source-available drop-in replacement for MongoDB Community Edition without commercial subscription licensing.

Verdict

Choose Apache CouchDB if your application benefits from flexible documents and synchronization across disconnected peers, and your team is prepared to self-host and resolve conflicts. Its free license and replication model are compelling for that use; look elsewhere if managed operations or avoiding revision conflict work is the priority.

	Apache CouchDB	PostgreSQL
Free plan	Yes	Yes
Free trial	No	No
Paid from	Free	Free
Open source	No	No
Platforms	api, Linux, macOS, self-hosted, Web, Windows	Linux, macOS, self-hosted, Windows
Free plan	Yes	Yes

Apache CouchDB vs PostgreSQL

Apache CouchDB

PostgreSQL