Prettify behaviour on blur is not a good user experience.

[pksjce]

Hey @fkling - To continue the earlier discussion from https://github.com/fkling/astexplorer/pull/213, here is how codesandbox added prettier support. They have a button, on clicking of which, the code formats itself. Maybe we could convert that toggle into a button like you suggested?

[fkling]

Yep, that seems reasonable to me!