I’m working on a Vue/Nuxt project where my client reports that the website is slow — especially when loading a selection window and when fetching JSON data.

However, the slowness is not very noticeable on my local machine, so I’d like to know the best way to measure, diagnose, and fix performance issues in Vue/Nuxt apps.

Here’s a brief summary of my setup:

Framework: Nuxt 3 / Vue 3

Data source: Static JSON files fetched from the backend

Deployment: hosted on VPS, Nginx

Issue: Client says pages are slow to load.

What I’d like to know:

The best tools or methods to accurately measure loading performance (locally or remotely).

How to use Chrome DevTools or Vue DevTools to spot bottlenecks (like unnecessary re-renders, repeated API calls, or heavy JSON loads).

Common optimizations specific to Vue/Nuxt (e.g., caching, lazy loading, bundle size reduction).

How to simulate real-world performance (since my system is fast, but client’s isn’t).

Any step-by-step advice or examples would be appreciated. Thanks in advance!