# Demonstration of pydantic-core unit tests running in the browser

[Run tests in your browser at this web link](https://githubproxy.samuelcolvin.workers.dev/pydantic/pydantic-core/blob/main/wasm-preview/index.html).

To test with a specific version of pydantic-core, add a query parameter `?pydantic_core_version=...` to the URL, e.g. `?pydantic_core_version=v2.4.0`, defaults to latest release.

This doesn't work for version of pydantic-core before v0.23.0 as before that we built 3.10 binaries, and pyodide now rust 3.11.

If the output appears to stop prematurely, try looking in the developer console for more details.

For pydantic-core versions prior to `2.2.0`, tests will freeze at  at 10-15% of the way through on Chrome due to a suspected V8 bug, see [pyodide/pyodide#3792](https://github.com/pyodide/pyodide/issues/3792) for more information.
