Mock Service Worker vs Tonic.ai

Free and open source

Quote on request

Free and open source. You pay in engineering time and CI minutes.

Enterprise quote-based pricing by data volume and connected databases.

Everything, self-hosted

Free trial.

Category standard

OSS community · since 2020

Established

Tonic.ai · since 2018

• One set of handlers reused across unit, component, E2E and local development.
• Application code is completely unaware it is being mocked — no test-only branches.
• Supports REST and GraphQL with the same model.

• Preserves referential integrity and statistical distribution, so applications behave as they do in production.
• Directly addresses the GDPR and HIPAA exposure created by production data in lower environments.
• Subsetting produces a small but coherent slice rather than a full copy.

• JavaScript ecosystem only.
• Service Worker registration adds a setup step and occasional caching confusion.
• Handlers can drift from the real API without contract verification.

• Expensive, with enterprise-only pricing.
• Initial configuration of sensitive-field classification takes real effort.
• Adds a pipeline stage that must be maintained as the schema evolves.

Front-end teams that want one mocking approach across every kind of test.

Organisations that currently copy production data into staging and know they should stop.