Next.js performance checklist for small business sites

Small business sites don't usually get slow because of one big mistake. They get slow one widget at a time: a chat bubble, a heavy hero video, three analytics scripts, a carousel nobody uses. Next.js gives you good defaults, but it can't stop you from adding things.

Here is the checklist I run through on a typical marketing or content site.

Render as much as possible ahead of time

Make pages static. Most small business pages don't change per visitor. If a page can be generated at build time, it can be served from a CDN close to the user, which is about as fast as the web gets.
Be careful with anything that makes a page dynamic. Reading cookies or headers in a layout, for example, can turn every page into a server render. Check the build output to see which routes are static.

Images

Use next/image with explicit width and height, so the browser reserves space and the layout doesn't jump.
Size images for where they're shown. A 4000px photo in a 600px card is the most common performance problem I see.
Only mark the main hero image as priority. Everything below the fold can load lazily.

Fonts

Load fonts with next/font. It self-hosts the files and adjusts the fallback font to reduce layout shift.
Use one or two families and only the weights you actually need.

Third-party scripts

This is usually where the biggest wins are.

List every script on the site and ask who uses its data. Remove the ones nobody looks at.
Load the rest late. Chat widgets and similar tools can wait until the page is interactive, or until the user clicks a button that opens them.
Prefer simple embeds. A link to a booking page is lighter than an embedded calendar on every page.

Client JavaScript

Keep components on the server by default. Only add "use client" where you need state or browser APIs, like a menu toggle.
Push client components down the tree. A small interactive button shouldn't turn the whole page into client code.
Watch your dependencies. A date library or an icon pack can quietly add a lot to every page.

SEO basics that overlap with speed

A unique title and description on every page.
A sitemap and a robots file.
Real headings in order, descriptive link text, and alt text on images.

These don't make a site faster, but they're cheap to get right, and Lighthouse checks them alongside performance.

Measure the right way

Run Lighthouse in mobile mode, in an incognito window, against a production build. Development mode is much slower and the numbers mean little.
Check field data too. Lab tests are a snapshot. Search Console's Core Web Vitals report shows what real visitors experience over time.
Measure before and after each change, with the same setup, so you know what actually helped.

Most of these fixes take hours, not weeks. If your site feels slow and you're not sure where to start, the third-party scripts and the images are usually the first place to look.