The file sizes shown in the visualizer are larger than the ones reported by Vite on the command line or that show up on disk after building. To see this, you can just clone vitesse, install its packages, and run vite-bundle-visualizer for it.

On the command line, a file size of 153kb is shown for the main javascript asset:

Similarly, on disk, the file appears to be 150kb:

But in the visualizer, the same file (with the same hash in the name, so it should have the same contents) is reported to be 461kb: