Hey everyone,

I'm running a Next.js app on Vercel, and I'm facing an urgent issue. Everything works perfectly in local testing, but some users (mostly on Mac browsers) report that certain pages suddenly start glitching badly, and sometimes the browser tab crashes completely.

The strange part is:

I can't reproduce it locally

Vercel logs show no server errors

After reopening the app, it sometimes works again

So it seems like the issue is happening entirely on the client/browser side.

I'm trying to understand:

How do teams usually monitor frontend errors in production?

Are there any simple or open-source tools that capture browser crashes, JS runtime errors, or user sessions?

What's the best way to debug issues that only happen on real users' machines?

Any suggestions or tools people commonly use would really help. I'm trying to find a reliable way to track down the root cause.