https://github.com/lydell/source-map-visualize
> [Tobias Koppers]' [source map visualization] is a great tool for inspecting
> source maps, both for source map consumers trying to set up their build tool
> correctly, as well as for developers of source map producing compilers.
> However, uploading the generated file, the source map and all the source files
> is tedious. source-map-visualize simplifies that. Just type:
>
> $ source-map-visualize fixtures/example.js
>
> ... and the visualizer will be opened in your default browser with all the
> files pre-loaded! (`fixture/example.js` exists in this repository, so you
> could try that straight away!)
[Tobias Koppers]:
https://github.com/sokra/
[source map visualization]:
https://sokra.github.io/source-map-visualization/