Questions Asked Frequently Enough

Can I use nunjucks in node and the browser/client-side?

Yes.

Can I use the same templates between nunjucks and jinja2? What are the differences?

Kind of. There are enough differences that it might take some work. The first problem is that nunjucks lets you access native JavaScript constructs, while jinja2 lets you access Python. This means that there are minor gotchas like the boolean literal being true in nunjucks but True in jinja2, and if you call native methods on arrays the API will be different.

However, if you avoid accessing the native language features (like {{ str.trim() }}) and rely solely on filters and pure templating features, it should be easy to make templates compatible.

Nunjucks has experimental support for installing APIs into the templating environment to help with Jinja compatibility. See installJinjaCompat.

Additionally, there are few jinja2 features not implemented in nunjucks:

Lastly, any custom Python filters and extensions will have to be written in JavaScript.