How long does it take to run this checklist on a template?

Approximately fifteen to twenty minutes per template if the demo is publicly accessible. Checks 1 and 2 take five minutes on PageSpeed Insights. Check 4 takes two minutes in page source. Checks 5 and 6 require repository access and take five to ten minutes. The remaining checks take one to two minutes each once you know what to look for.

Should I run this checklist on free templates too?

Yes. Free templates have the same production requirements as paid templates if the project they are used for will be deployed publicly. The checklist criteria do not change based on price. What changes is the expectation of the result - free templates fail more checks on average, and the decision to use them anyway requires explicitly budgeting the remediation time.

What if a template passes 11 of 12 checks?

Assess which check failed. A failure on Check 10 (license) may be a dealbreaker regardless of everything else. A failure on Check 8 (CSS bundle size) at 18kb instead of 15kb is a minor issue. A failure on Check 4 (structured data) means building the SEO architecture yourself - budget 17 to 29 hours.

Is it worth buying a template that fails Check 3 (App Router) if the price is very low?

Not for any project that will be maintained or extended. The Pages Router works today. It is not receiving new features. Migrating from Pages Router to App Router is a non-trivial project. The low price of a Pages Router template is not a discount - it is the cost of a future migration baked in.

Does passing all 12 checks guarantee a good template?

It guarantees that the template meets production technical standards. Design quality, component completeness, and category-specific features (e-commerce functionality, auth architecture, CMS integration) are separate evaluations. This checklist eliminates templates that will fail in production. It does not guarantee that a template is the best choice for your specific project.

Why do templates fail these checks if they are sold as production-ready?

"Production-ready" in template marketing typically means "the demo works." It does not mean the template meets the technical standards that a production deployment actually requires. The term is used loosely. This checklist provides a precise definition of what production-ready means technically.

Can I send this checklist to a client to explain why a template costs more than they expected?

Yes. The checklist provides a concrete framework for explaining that template quality varies significantly and that cheap or free templates have hidden costs. Showing a client a failed checklist result is more convincing than explaining that the template is "low quality" - it quantifies what low quality means in specific, testable criteria.

GUIDESMARCH 10, 202618 MIN READ

The Next.js Template Checklist: 12 Tests Before You Buy

You are about to spend money on a Next.js template or download a free one and spend three weeks on it. This checklist helps you inspect architecture, SEO readiness, and maintenance risk before you commit.

You are about to spend money on a Next.js template - or download a free one and spend three weeks on it. Either way, the decision commits you to an architecture, a quality level, and a maintenance burden for the life of the project. Most buyers skip the inspection step entirely. They look at the demo, check the price, and buy.

This is a mistake that costs real money.

After building production Next.js infrastructure for clients across multiple industries, we compiled the twelve questions that separate templates worth buying from templates that look good in screenshots and fall apart in production. Run every template you evaluate - free or paid, marketplace or independent studio - through this checklist before committing.

Most templates fail at least four of them. Some fail eight.

How to Use This Checklist

For each test, you need either the live demo URL, the GitHub repository, or the page source. All twelve checks can be completed in under twenty minutes for any template that makes its demo publicly accessible.

If a seller does not provide a public demo URL, that is already a red flag. Treat it as a failed inspection on checks 1, 2, and 3.

CHECK 1 - Run the Demo on PageSpeed Insights

What to do: Open pagespeed.web.dev, paste the demo URL, and run the test on mobile.

What to look for:

Performance: 95 or above
Accessibility: 100
Best Practices: 100
SEO: 100

Why this matters: The Performance score on mobile reflects the real experience of a user on a 4G connection - which is the majority of web traffic globally. Anything below 90 on Performance means the template has structural issues that will require remediation before delivery. Below 80 means the architecture is fundamentally wrong.

What most templates score: Independent testing of templates from major marketplaces shows average Lighthouse Performance scores of 62 to 74 on mobile. Several templates marketed as "high performance" score below 60 on mobile when tested on real deployment infrastructure.

Pass threshold: 95+ on Performance. 100 on Accessibility, Best Practices, and SEO.

Red flags:

No demo URL provided
Demo hosted on a localhost or non-production URL
Demo that only works on desktop (seller avoided mobile test)
Performance score below 90 with no acknowledged remediation guide

CHECK 2 - Inspect the Core Web Vitals

What to do: In the PageSpeed Insights report, scroll down to "Core Web Vitals Assessment" and look at the three metrics that Google uses as ranking signals.

What to look for:

LCP (Largest Contentful Paint): under 2.5s, ideally under 1.2s
INP (Interaction to Next Paint): under 200ms
CLS (Cumulative Layout Shift): under 0.1

Why this matters: Core Web Vitals are Google's confirmed ranking signals. A template that fails Core Web Vitals is a template that will underperform in search from its first day of deployment. No amount of content quality or link building fully compensates for a site that Google has flagged as a poor user experience.

What most templates score: CLS failures are particularly common in templates that use tags without explicit width and height attributes - images that shift the layout as they load. LCP failures occur frequently in templates with large hero images that are not preloaded.

Pass threshold: Green on all three Core Web Vitals.

Red flags:

Yellow or red on any Core Web Vital metric
LCP above 2.5 seconds on mobile
CLS above 0.1 (indicates layout shift from unspecified image dimensions or web fonts)

CHECK 3 - Verify the Next.js Architecture

What to do: Look at the repository structure. If access is not available, check the documentation for mentions of App Router, Pages Router, or the Next.js version.

What to look for:

/app directory with page.tsx files = App Router (correct)
/pages directory with index.tsx files = Pages Router (legacy)

Why this matters: Next.js introduced the App Router as stable in version 13.4 (May 2023). The App Router uses React Server Components by default, which dramatically reduces the JavaScript sent to the browser and improves performance. The Pages Router is the legacy architecture - functional but not receiving new features and not the foundation to build new projects on in 2026.

A template built on the Pages Router is not a 2026 template regardless of when it was published. It is a template built on a deprecated architecture with a future migration cost built in.

What most templates use: A significant portion of Next.js templates on major marketplaces use the Pages Router. Some are labeled as "Next.js 14" while using the Pages Router - which is technically possible (Pages Router still exists in Next.js 14) but architecturally wrong for new projects.

Pass threshold: App Router only. No /pages directory in the project root.

Red flags:

Pages Router architecture
Hybrid architecture (both /app and /pages) without clear documentation of why
getServerSideProps or getStaticProps patterns in the documentation (Pages Router API)
No mention of App Router or Server Components anywhere in the documentation

CHECK 4 - Check for Structured Data

This is the check most templates fail. It is also the check most buyers never perform.

What to do: Open the demo URL in your browser. Right-click, select "View Page Source." Press Ctrl+F and search for @context.

What to look for:

"@context": "https://schema.org" in a