Vite 8 doubled filesize

[repulsio]

Describe the bug

So sad that Vite 8 now builds an index.js of size 1.5 MB, when it used to be 951 KB in Vite 7.3.1...

The only thing I changed for my project was updating Vite from 7.3.1 to 8.

What happened? Is it no longer checking code paths and just blindly including everything?

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Reading the release notes, it seems that Vite 8 should now build faster with rolldown, but no build speed gain is worth increasing the filesize by so much - it's so critical to keep web filesizes as low as possible for fast load times...

[Boshen]

Close as no reproduction.

[repulsio]

@Boshen I recommend you get any one of your projects and try see the difference in build sizes for Vite 7.3.1 and Vite 8. It's a huge increase

Instead of hiding this issue, can you at least share this huge concern with the team?

I can't release our whole team's repo here

[github-actions]

Hello @repulsio. Please provide a minimal reproduction using a GitHub repository or StackBlitz. Issues marked with needs reproduction will be closed if they have no activity within 3 days.

[repulsio]

I think I narrowed down the issue.

I have a large class called Core that I can either run on the main thread (index.js) or worker thread (worker.js).

I have a boolean USE_WEB_WORKER = true to control whether Core runs in the main or worker thread.

Vite 7.3.1 smartly detected this boolean and didn't include any Core code in index.js (951 KB) and only in worker.js (1.5 MB).

However, Vite 8 includes Core code in both index.js (1.5 MB) and worker.js (1.5 MB) regardless of the boolean value for USE_WEB_WORKER.