Testcontainers vs Gretel.ai

Free tier available

Free tier available

Free. Testcontainers Cloud, which offloads container execution, is a paid Docker product.

Consumption-based on generated records; enterprise agreements available.

The libraries are free and open source.

Free tier with a monthly credit allowance.

Category standard

AtomicJar (Docker) · since 2015

Emerging

Gretel (NVIDIA) · since 2019

• Tests run against the real database engine, so dialect and behaviour differences surface early.
• Containers are disposable, which removes shared-state flakiness entirely.
• Excellent language coverage with idiomatic APIs.

• Formal differential-privacy guarantees rather than best-effort masking.
• Synthetic data preserves statistical relationships useful for analytics and model training.
• Privacy and quality scores make the trade-off explicit.

• Requires a Docker daemon in CI, which not every environment provides.
• Container startup adds seconds to each test run unless reused carefully.
• Heavier resource usage than in-memory alternatives.

• Model training adds time and cost compared to rule-based masking.
• Overkill when simple anonymisation would satisfy the requirement.
• NVIDIA acquisition changes the strategic outlook.

Integration tests that currently use in-memory databases and lie to you.

Regulated organisations that need shareable data with defensible privacy properties.