# Why test on DuckDB instead of on my platform?

> DuckDB runs on your machine with no cluster, so a golden test takes seconds and spends no warehouse compute, which makes testing on every save practical.

Speed and cost. [DuckDB](https://emolysis.com/platforms/duckdb) runs on your machine, starts instantly and needs no cluster, so a golden test takes seconds and spends no warehouse compute. That makes it practical to run the tests on every save, not only before a release.

DuckDB is the judge for the expected outputs; the same transformation is then translated into your platform's dialect for deployment. DuckDB cannot show everything, though: permissions, performance on full data and platform-specific behavior only appear on the platform.

That is why each template's cases also run on the real platform before the template is marked ready there, and why each [platform profile](https://emolysis.com/docs/platform-profiles) lists known traps that lint rules check for. A template is only called ready on a platform after it passes on that platform. See [golden tests on DuckDB](https://emolysis.com/docs/golden-tests).

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Page: https://emolysis.com/faq/why-test-on-duckdb. Emolysis is a product of Bandpey GmbH, Munich, Germany. It is in private development, and nothing is released yet.