lifelines

Survival analysis library in pure Python

EstablishedOpen SourceLow lock-in

Pricing

Free tier

Flat rate

Adoption

Cooling

License

Open Source

Data freshness

Aging · Jun 8, 2026

Overview

What is lifelines?

Lifelines is a comprehensive survival analysis library written entirely in Python. It provides tools for estimating and plotting survival functions, hazard rates, and more.

Key differentiator

Lifelines stands out with its comprehensive set of tools and models specifically tailored for survival analysis in pure Python.

Capability profile

Capability Radar

Ease of StartEcosystemValueMaturityFlexibilityScale Ready

Honest assessment

Strengths & Weaknesses

↑ Strengths

Estimation of survival and hazard functionsmedium

Cox proportional hazards modelmedium

Aalen additive modelmedium

Kaplan-Meier estimatormedium

Nelson-Aalen estimatormedium

↓ Weaknesses

Limited support for advanced survival analysis techniqueshigh

Does not include complex models like joint frailty models or multi-state models out-of-the-box

Poor documentation for certain features and methodsmedium

Some advanced functionalities lack detailed examples or explanations in the official documentation

Performance issues with large datasetshigh

Estimation of survival functions can be slow and memory-intensive when dealing with very large datasets

Limited integration options with other data science toolsmedium

Does not natively integrate well with popular Python libraries such as pandas or scikit-learn for seamless workflow

Fit analysis

Who is it for?

✓ Best for

Research teams needing comprehensive survival analysis tools written in Python

Academics working on time-to-event data who prefer open-source solutions

Business analysts looking to predict customer churn using survival models

✕ Not a fit for

Teams requiring real-time analysis as lifelines is designed for batch processing

Developers needing a web-based interface, as it's primarily a Python library

Cost structure

Pricing

Free Tier

Available

Open source — free to use

Starts at

$0

Model

Flat rate

Enterprise

None

Performance benchmarks

How Fast Is It?

Ecosystem

Relationships

Next step

Get Started with lifelines

Step-by-step setup guide with code examples and common gotchas.

View Setup Guide →