Scan your site.
Paste a URL. You get a real Lighthouse run - the same engine Google ranks on - and a plain answer to the question a score never tells you: what is actually slowing this page down, your code or everything you bolted onto it.
Runs Google PageSpeed Insights against the public URL, mobile profile. Nothing is stored and no login is needed.
The score is not the finding.
A performance score compresses six measurements into one number, which is why it tells you almost nothing you can act on. Total Blocking Time is usually the one that matters: it is the stretch where the page is painted but ignores taps, and it is the metric visitors experience as "this is broken".
Across the production Next.js apps I have measured, the same split keeps appearing - either a handful of analytics tags are eating the main thread, or a single one of your own chunks is. Those look identical from the outside and need completely different fixes, which is the one thing this scan settles for you.
If the number is bad.
A scan tells you where the page hurts. It does not tell you why the bundle got that way, what breaks when you change it, or what to do first. That is what the paid audit covers - a written report, a prioritized fix list, and effort estimates against your actual repo.