whichdb
vs

Sphinx vs Xapian

Sphinx: Veteran C++ full-text search server with SphinxQL, still shipping as Sphinx 3. Xapian: Mature C++ probabilistic full-text search library with bindings for a dozen languages.

key differences

  • Licensing: Sphinx is proprietary (Sphinx 3: free binaries, dual-licensed (2.x was GPL-2.0)); Xapian is open source (copyleft) (GNU GPL v2 or later).
  • Transactions: Sphinx offers none ACID; Xapian offers limited.
  • Only Sphinx has secondary indexes, vector search, json.
  • Only Xapian has transactions.
  • Xapian can run embedded in your application process.

choose sphinx for

  • +Maintaining existing Sphinx deployments
  • +MySQL-backed site search
  • +Forum and classifieds search

best at · Search, Vector search

choose xapian for

  • +Search inside desktop and server applications
  • +Indexing documentation, mail archives or websites with Omega
  • +Search in Python, Perl or PHP apps without running a search server

best at · Search, Embedded

SphinxVeteran C++ full-text search server with SphinxQL, still shipping as Sphinx 3.
XapianMature C++ probabilistic full-text search library with bindings for a dozen languages.
overview
Primary model
Search Engine
Search Engine
Also supports
Vector
–
Type
Database engine
Embedded library
Status
Active
Active
Developer
Sphinx Technologies Inc.
Xapian project (Olly Betts and contributors)
First release
2001
2002
Latest version
3.9.1 (Dec 19, 2025)
2.1.0 (Aug 13, 2026)
License
ProprietarySphinx 3: free binaries, dual-licensed (2.x was GPL-2.0)
Open source (copyleft)GNU GPL v2 or later
Free tier
✓
✓
popularity
WhichDB Score
5.2
18.0
Rank
#389
#185
GitHub stars
–
877
Stack Overflow questions
–
105
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Medium (≤ 10 TB)
Horizontal scaling
Manual
Manual
Multi-region
None
None
ACID
None
Limited
Consistency
Eventual
Strong
Schema
Strict
Schemaless
Architecture
Single node, Client server
Embedded, Client server
deployment
Self-hosted
✓
✓
Vendor-managed cloud
—
—
Serverless
—
—
Embedded
—
✓
Edge
—
—
Clouds
–
–
capabilities
Transactions
—
✓
Joins
—
—
Secondary indexes
✓
—
Full-text search
✓
✓
Vector search
✓
—
Geospatial
✓
✓
JSON
✓
—
Change data capture
—
—
Triggers
—
—
Stored procedures
—
—
Materialized views
—
—
TTL / expiry
—
—
Pub/Sub
—
—
Columnar storage
—
—
In-memory
—
—
Durable persistence
✓
✓
Compression
✓
✓
Encryption at rest
—
—
Role-based access
—
—
Time travel
—
—
Branching
—
—
Online schema changes
—
—
Streaming ingest
—
—
Offline sync
—
—
Runs in WebAssembly
—
—
interfaces
Query languages
SphinxQL
Xapian query parser syntax, Query API
Client languages
PHP, Python, Java, Ruby, C
C++, Python, Perl, PHP, Java, Ruby, C#, Tcl
Best for
Search, Vector search
Search, Embedded
Add more to this comparisonNot sure either fits? Try smart match

Sphinx vs Xapian: FAQ

What is the difference between Sphinx and Xapian?

Sphinx: Veteran C++ full-text search server with SphinxQL, still shipping as Sphinx 3. Xapian: Mature C++ probabilistic full-text search library with bindings for a dozen languages. Licensing: Sphinx is proprietary (Sphinx 3: free binaries, dual-licensed (2.x was GPL-2.0)); Xapian is open source (copyleft) (GNU GPL v2 or later). Transactions: Sphinx offers none ACID; Xapian offers limited. Only Sphinx has secondary indexes, vector search, json.

When should I choose Sphinx over Xapian?

Choose Sphinx for maintaining existing Sphinx deployments; MySQL-backed site search; and forum and classifieds search. Choose Xapian for search inside desktop and server applications; indexing documentation, mail archives or websites with Omega; and search in Python, Perl or PHP apps without running a search server.

Is Sphinx or Xapian more popular?

Xapian ranks #185 on the WhichDB Score (18.0/100) and Sphinx ranks #389 (5.2/100). Popularity is not fit: check the requirements that matter for your project.

Are Sphinx and Xapian open source?

No. Sphinx is proprietary, closed-source software. License: Sphinx 3: free binaries, dual-licensed (2.x was GPL-2.0). Yes. Xapian is open source. License: GNU GPL v2 or later.