I Rebuilt a Slow WordPress Website with Next.js — Here’s What Changed

I recently worked on a WordPress website that looked fine on the surface, but its performance told a different story.

The old setup had a slow backend response and a large amount of frontend overhead.

Before rebuilding it, the Lighthouse performance score was around 38, with an LCP of several seconds.

Instead of trying to fix every problem inside the existing WordPress theme, I changed the architecture.

The new setup uses:

• WordPress as the CMS

• Next.js for the frontend

• WordPress REST API for content

• Vercel for frontend deployment

The result was a much lighter frontend and significantly faster page delivery.

After the migration, the site reached around 98 in Lighthouse Performance during my testing, with LCP dropping to under 1 second.

The important lesson wasn't simply “Next.js is faster than WordPress.”

The real lesson is that performance problems often come from the architecture, theme, plugins, assets, and server configuration working together.

Sometimes optimizing the existing WordPress installation is the right choice.

Sometimes rebuilding the frontend is the better solution.

The key is to measure first and choose the architecture based on the actual bottleneck.

That's the approach I use when working on performance-focused websites.