Direct answer
A Next.js performance budget should limit unnecessary client JavaScript, control images, reserve layout dimensions, keep fonts stable, check Core Web Vitals risk, and test priority routes.
The useful version of this topic is practical: it should help a buyer make a better website decision, not just define a term.
Practical framework
Use the framework below to turn the topic into a page, brief, audit, or approval checklist.
- Server-render marketing content by default
- Keep client components intentional
- Optimise hero and repeated images
- Reserve dimensions for media and cards
- Limit third-party scripts
- Test mobile first viewport and key CTAs
Method proof to prepare
When public client proof is not available, method proof can still make the decision inspectable without inventing outcomes, reviews, awards, or rankings.
- Bundle review
- Image inventory
- Layout shift checklist
- Mobile screenshots
- Priority route performance notes