Pre-launch checks for vibe-coded sites

Building with AI assistance is fast. You can go from idea to deployed site in hours. But speed creates blind spots. The same tools that help you ship quickly don't catch the security misconfigurations or performance issues that accumulate when you're focused on features.

Before launch, run your site through a handful of free tools that check what the builder didn't.

Start with Cloudflare

Before checking anything else, put Cloudflare in front of your site. The free tier includes a Content Delivery Network (CDN), automatic SSL, and DDoS protection. You point your DNS at Cloudflare, and they proxy all traffic to your origin server.

The CDN caches static assets at locations worldwide. Visitors get files from the nearest data centre instead of your host. For a vibe-coded project on basic hosting, this alone can cut load times significantly.

The DDoS protection is unmetered on the free plan. If someone decides to hammer your site, Cloudflare absorbs it. You don't pay extra hosting costs or go offline. For a new project with no security budget, this matters.

Cloudflare can also add security headers and provides basic bot protection. It won't fix application-level vulnerabilities, but it raises the bar considerably.

Security headers and TLS configuration

Your site probably has HTTPS. What it might not have is the full set of security headers that modern browsers expect.

SSL Labs grades your TLS configuration. It checks certificate validity, protocol support, cipher suites, and known vulnerabilities. Most hosting platforms pass by default, but custom configurations often drift. A grade below A usually means something needs attention.

Security Headers focuses on HTTP response headers. Content-Security-Policy, Strict-Transport-Security, X-Frame-Options, Referrer-Policy. These headers tell browsers how to behave when loading your site. Missing headers don't break anything visibly, which is why they're easy to forget.

Barrion combines both checks and adds cookie security, CORS configuration, and DNS settings. The free scan runs passively, no authentication required, and returns results in under a minute. The remediation steps are specific enough to act on.

Deeper vulnerability scanning

If you're handling user data or payments, surface-level header checks aren't enough.

Snyk scans your codebase for known vulnerabilities in dependencies. The free tier covers open source libraries and gives you remediation advice. It integrates with GitHub, so you can catch issues before they reach production. For vibe-coded projects with unfamiliar dependencies, this matters. AI assistants pull in packages without explaining the supply chain risk.

Probely takes a different approach. It's a Dynamic Application Security Testing (DAST) scanner, meaning it tests your running application the way an attacker would. It simulates requests, looks for injection points, and reports what's actually exploitable. The free tier is limited, but the initial scan shows where your biggest exposures are.

Neither tool replaces a proper security review. But they catch the obvious mistakes, which in vibe-coded projects tend to be the majority.

Performance testing

Performance problems compound. A slow site loses visitors before analytics can even measure them.

PageSpeed Insights reports Core Web Vitals, the metrics Google uses as a ranking signal. Largest Contentful Paint, Cumulative Layout Shift, Interaction to Next Paint. It tests both mobile and desktop, and shows exactly which elements are dragging down your score.

The distinction between lab data and field data makes a big difference. Lab data comes from a simulated test run immediately. Field data comes from real users over 28 days. A new site won't have field data, so focus on the lab results and the specific recommendations.

Pingdom gives you a waterfall view of every request your page makes. You can see which files load slowly, which third-party scripts add latency, and where the bottlenecks are. It's older technology than PageSpeed, but the waterfall visualisation is sometimes clearer for debugging.

The useful output from both tools isn't the score. It's the specific list of slow resources and missing optimisations.

Limits of automated scanning

These tools don't test authentication flows. They don't check business logic. They don't know if your database queries leak information they shouldn't. Automated scans catch configuration problems and known vulnerability patterns. They don't reason about your application.

For most pre-launch checks, that's enough. You're looking to eliminate the easy mistakes before real users find them. A site that passes these checks isn't secure or fast by definition, but it's not leaking obvious problems either.

Run them once before launch. Set up monitoring for the security tools. Check performance again after your first traffic spike.