Great Expectations
Data validation — test, document, profile your data
📋 Overview
Great Expectations is an open-source data validation tool that lets you test, document, and profile your data — ensuring quality and catching issues before they impact downstream processes. Unlike dbt tests (which are SQL-only), Great Expectations provides a Python API for complex validations, automatic profiling, and beautiful data docs.
✨ Key Features
- •10K+ GitHub stars — data validation standard
- •Test, document, profile data
- •Beautiful data docs
- •Integrates with dbt, Airflow, Spark
- •Apache 2.0 licensed
- •Beautiful data docs
- •Complex validations
🎯 The Problem It Solves
Data quality issues silently corrupt ML models and analytics. Great Expectations provides automated testing and documentation to catch issues early.
🔧 How It Works
You define expectations (validation rules) for your data — column types, value ranges, uniqueness, etc. Great Expectations runs these expectations against your data, generates data docs with profiling statistics, and alerts on failures. Integrates with dbt, Airflow, and Spark.
🚀 Installation & Quick Start
Installation
See websiteQuick Start
- See documentation
✅ Pros
- •Best data docs and profiling
- •Complex validations
- •Apache 2.0 licensed
- •Beautiful data docs
- •Complex validations
- •Active community
❌ Cons
- •Steep learning curve
- •Python API verbose
- •Cloud version maturing
- •Steep learning curve
💬 Practitioner Verdict
“Great Expectations is the best open-source data validation tool — the data docs and profiling are genuinely differentiated. The trade-off: steep learning curve, the Python API can feel verbose, and the cloud version is still maturing. For teams that need data quality assurance, Great Expectations is the default.”
Self-Hosted (Free)
Open source, MIT/Apache licensed. Run it yourself.
⭐ Star & Clone on GitHubFree forever. Your infrastructure, your data.
📊 Specifications
- Language
- Python
- License
- Apache-2.0
- Platform
- Linux, macOS, Windows
- Supported Models
- REST API, CLI
💰 Pricing Reality
100% free Apache 2.0. No paid tier. Cloud (GX Cloud) is in beta.