Mock Service Worker vs Mockaroo
Feature checklists rarely decide anything. What decides it is the pricing metric, who has to write the tests, and which limitation you can live with.
Entry price
Free and open source
Open sourceFrom $60 per year (indicative, Silver)
Free tierWhat drives the bill
The metric that actually scales your invoice.
Free and open source. You pay in engineering time and CI minutes.
Cheap for what it does; higher tiers raise row limits and add API quota.
Free tier
Everything, self-hosted
Free for up to 1,000 rows per download and a limited number of saved schemas.
Open source
MIT
Self-hostable
No-code authoring
Languages
Platforms
Fits teams
Adoption
Category standard
OSS community · since 2020
Established
Mockaroo LLC · since 2014
Strengths
- 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.
- No code required — an analyst or tester can design a dataset themselves.
- Very large library of realistic field types including regional formats.
- Formula fields allow simple business rules between columns.
Limitations
- JavaScript ecosystem only.
- Service Worker registration adds a setup step and occasional caching confusion.
- Handlers can drift from the real API without contract verification.
- Referential integrity across related tables is limited.
- Free-tier row limits are low for realistic volume testing.
- Data is generated on a third-party service, which needs a privacy check for schema sensitivity.
Best for
Front-end teams that want one mocking approach across every kind of test.
Quickly producing a realistic dataset for a demo, a load test or a new environment.
Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.