Is there a way to launch a separate devtools after a build?

[WoodyWoodsta]

We'd like to move away from 3rd party bundle visualisation (tree-map view in particular, like Sonda) and use Vite Devtools. It seems like devtools is currently only possible while the app is running.

Are there plans to enable something that can be run independently of a server/application for post-build analysis?

[wmorin]

Yes, you can already do this without the app running. Two things tripped me up when I tried it with Vite 8.3 and @vitejs/devtools 0.7.6:

1. @vitejs/devtools-rolldown is an optional peer dependency, so npm does not install it. Without it there is no Rolldown panel at all.
2. A normal vite build only writes the Rolldown build data (to node_modules/.rolldown) if you turn it on:

// vite.config.js
export default defineConfig({
  build: { rolldownOptions: { devtools: {} } },
})

Then:

npm i -D @vitejs/devtools-rolldown
vite build
npx vite-devtools        # serves DevTools on :9999 from the saved build data
npx vite-devtools build  # static output in .vite-devtools/

The standalone server worked for me with no dev server or app running, including the chunks treemap data (add --no-open in CI or Docker, otherwise it crashes trying to open a browser). The static build is flagged as experimental (DTK0010): its dump had the session list and summary but no chunk/module details, so for the treemap I'd use vite-devtools for now.

One caveat: devtools.build.withApp: true wrote dist/__devtools fine but then started a server on :9999 and vite build never exited for me, so I'd avoid it in CI.

Source for where the data is read: https://github.com/vitejs/devtools/blob/main/packages/rolldown/src/node/rpc/utils.ts

Do you need the report to be a static artifact you can host, or is running vite-devtools locally after the build enough?