Prism vs Faker

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.

PrismFaker

Entry price

Free and open source

Open source

Free and open source

Open source

What drives the bill

The metric that actually scales your invoice.

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

Free tier

Everything, self-hosted

Open source

Apache-2.0

MIT

Self-hostable

No-code authoring

Languages

JavaScriptCodeless

JavaScriptTypeScriptPythonJavaRubyPHPGo

Platforms

API

WebAPI

Fits teams

StartupScale-up / mid-marketEnterprise

Solo / side projectStartupScale-up / mid-marketEnterprise

Adoption

Established

Stoplight (SmartBear) · since 2017

Category standard

OSS community · since 2010

Strengths

The mock is generated from the spec, so it cannot silently diverge from the contract.
Validation proxy mode checks that a real implementation matches its own spec.
Zero configuration beyond having an OpenAPI file.

Realistic, locale-aware data catches layout bugs that 'test test test' never will.
Seedable, so generated data is reproducible when a test fails.
Available in every major language with a similar API.

Limitations

Generated data has no referential integrity or business rules — that is your job.
Random data makes failures harder to reproduce unless you seed deliberately.
Not a substitute for production-shaped data at realistic volume.

Best for

Design-first API teams who want mocks that are provably in sync with the contract.

Every project that needs fixtures more realistic than placeholder strings.

Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.