splink
Fast probabilistic data linkage at scale
What it is and what it does
Splink is a Python package for probabilistic record linkage that solves the problem of matching and deduplicating records when no unique identifier exists. It uses the Fellegi-Sunter statistical model to compute match probabilities between record pairs, supporting fuzzy matching, term frequency adjustments, and user-defined comparison logic. The package works by comparing multiple non-correlated columns (such as name, date of birth, and location for persons), estimating model parameters through unsupervised learning, and clustering pairwise predictions to generate estimated entity IDs.
The package is designed for datasets with multiple descriptive columns and runs on a local laptop via DuckDB or scales to 100+ million records on big-data backends like AWS Athena or Spark. It includes interactive visualizations to help diagnose model performance and is widely used in government, academia, and the private sector. Runtime dependencies include altair, duckdb, igraph, jinja2, numpy, pandas, and sqlglot.
Use it for:
- Deduplicate customer or patient records in databases lacking a master identifier.
- Link census or survey data across years or sources to track population changes.
- Match company records across datasets with different naming conventions or incomplete information.
- Resolve entity identity in fraud detection or compliance workflows where records may be partially obscured.
- Consolidate data from multiple administrative systems without a shared key.
Worth the install?
AI-flagged interpretation of the facts on this page — verify before relying
Splink performs probabilistic record linkage and deduplication, matching records across datasets that lack unique identifiers by comparing multiple columns and assigning match probabilities.
Yes. Splink is actively maintained, has no known vulnerabilities, installs with low friction, and solves a specific and difficult problem (record linkage without unique identifiers) that has few mature alternatives in Python. The MIT license and strong maintenance signal (recent release, active repository) make it suitable for production use in government, academic, and commercial contexts. Install if you need to deduplicate or link records across datasets.
Install
splink on PyPI
pip
pip install splinkuv
uv add splinkpoetry
poetry add splinkInstalling splink
Before you install
Low friction install with a pure Python wheel. Actively maintained with a recent release (156 days ago) and 2338 repository stars. Supports current Python versions (3.9+).
License in practice
MIT license permits commercial and private use with minimal restrictions, making it suitable for government, academic, and private sector deployments.
Quickstart
pip install splink
import splink.comparison_library as cl
from splink import DuckDBAPI, Linker, SettingsCreator, block_on, splink_datasets
db_api = DuckDBAPI()
df = splink_datasets.fake_1000
settings = SettingsCreator(link_type="dedupe_only", comparisons=[cl.ExactMatch("name")])
linker = Linker(df, settings, db_api)
pairwise_predictions = linker.inference.predict()
Requires Python 3.9 or later; DuckDB is a runtime dependency for local linkage execution.
Verify before relying
- Whether optional backend installations (Spark, Athena, PostgreSQL) are commonly used or if DuckDB covers most use cases.
- Performance characteristics on datasets larger than the stated 'million records on a laptop in around a minute' benchmark.
- Whether the Fellegi-Sunter model's accuracy claims have been independently validated outside government case studies.
Package facts
| License | MIT (permissive) |
| Python support | supports the current Python release (<4.0.0,>=3.9.0) |
| Install friction | low — pure-Python wheel |
| Runtime dependencies | 7 — altair, duckdb, igraph, jinja2, numpy, pandas, sqlglot |
| Maintenance | actively maintained — 156 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 1,170,073/month — #4,271 on PyPI (30-day window, as of 2026-08-14) |
| Known vulnerabilities | none known (OSV.dev, checked 2026-08-14) |
Evidence: splink-4.0.16-py3-none-any.whl
Tags
More Information Analysis packages
A drop-in replacement for Python's standard…
permissive · top 100 on PyPI
pyarrowpyarrow provides Python bindings to Apache…
permissive · top 100 on PyPI
networkxNetworkX provides data structures and…
permissive · top 1,000 on PyPI
snowflake-connector-pythonConnects Python applications to Snowflake data…
permissive · top 1,000 on PyPI
contourpyContourPy calculates contours of 2D…
permissive · top 1,000 on PyPI
snowflake-snowpark-pythonSnowpark Python provides APIs to query and…
permissive · top 1,000 on PyPI
recordlinkageRecordLinkage identifies and matches records…
permissive · top 5,000 on PyPI
semhashSemHash deduplicates, filters outliers from,…
permissive · top 15,000 on PyPI
probablepeopleParses unstructured person and company names…
permissive · top 15,000 on PyPI
diff-match-patchProvides diff, match, and patch algorithms for…
permissive · top 5,000 on PyPI
fingerprintsGenerates simplified entity identifiers…
permissive · top 15,000 on PyPI
simhashComputes Simhash fingerprints for text and…
permissive · top 15,000 on PyPI
datasketchProvides probabilistic data structures…
permissive · top 5,000 on PyPI
fastclusterPerforms fast hierarchical agglomerative…
copyleft · top 15,000 on PyPI