Building a landing page / marketing site with JavaScript? Let us review it.
Expert code review for landing page / marketing sites built with JavaScript. We fix JavaScript-specific security gaps, optimize performance, and handle deployment. From $19.
Common JavaScript issues we find
Real problems from JavaScript codebases we've reviewed.
Prototype pollution
AI-generated code merges user-supplied objects into prototypes via Object.assign or spread operators without sanitization, enabling property injection attacks.
Loose equality comparisons
Using == instead of === leads to type coercion bugs where '0' == false, null == undefined, and other non-obvious truthy/falsy comparisons cause silent logic errors.
Unhandled promise rejections
Async functions without try/catch or .catch() handlers cause unhandled rejection warnings and silent failures in production.
Global variable leaks
Missing 'const' or 'let' declarations create implicit globals that pollute the global scope and cause unpredictable behavior across modules.
Landing Page / Marketing Site challenges to solve
Key landing page / marketing site concerns that AI-generated code often misses.
Page speed
Landing pages must load in under 2 seconds. AI tools generate bloated CSS, unoptimized images, and unnecessary JavaScript that slow loading. A 1-second delay in load time reduces conversions by 7%.
SEO fundamentals
Missing meta descriptions, incorrect heading hierarchy, no Open Graph tags, no structured data, and no sitemap. AI tools build the visible content but skip the invisible SEO infrastructure.
Form handling
Your contact form, waitlist signup, or demo request form must work flawlessly. AI-generated forms often lack validation, error messages, success confirmations, and backend integration.
Mobile responsiveness
Over 60% of traffic is mobile. AI-generated layouts sometimes break on small screens — overlapping elements, unreadable text, and inaccessible buttons. Every pixel matters for conversion.
What we check
Key areas we review for JavaScript landing page / marketing site projects.
Lighthouse performance score — targeting 95+
Image optimization — proper formats, sizing, lazy loading
SEO — meta tags, headings, structured data, sitemap, robots.txt
Form functionality — validation, error handling, backend integration
Not sure if your app passes? Our code audit ($19) checks all of these and more.
Start with a self-serve audit
Get a professional review of your JavaScript landing page / marketing site project at a fixed price.
External Security Scan
Black-box review of your public-facing app. No code access needed.
- OWASP Top 10 vulnerability check
- SSL/TLS configuration analysis
- Security header assessment
- Expert review within 24h
Code Audit
In-depth review of your source code for security, quality, and best practices.
- Security vulnerability analysis
- Code quality review
- Dependency audit
- Architecture review
- Expert + AI code analysis
Complete Bundle
Both scans in one package with cross-referenced findings.
- Everything in both products
- Cross-referenced findings
- Unified action plan
100% credited toward any paid service. Start with an audit, then let us fix what we find.
How it works
Tell us about your app
Share your project details and what you need help with.
Expert + AI audit
A human expert assisted by AI reviews your code within 24 hours.
Launch with confidence
We fix what needs fixing and stick around to help.
Frequently asked questions
Can you review a landing page / marketing site built with JavaScript?
Yes. We regularly audit JavaScript landing page / marketing site projects and understand the specific patterns and pitfalls of this combination. Our review covers security, performance, and deployment readiness.
What issues do you find in JavaScript landing page / marketing sites?
Common issues include prototype pollution and loose equality comparisons on the JavaScript side, combined with landing page / marketing site-specific concerns like page speed and seo fundamentals. We check for all of these and more.
How do I make my JavaScript landing page / marketing site production-ready?
Start with our code audit ($19) to get a prioritized list of issues. For JavaScript landing page / marketing site projects, the typical path is: fix security gaps, address landing page / marketing site-specific requirements, optimize JavaScript performance, then configure deployment. We provide a fixed quote after the audit.
How long does it take to audit a JavaScript landing page / marketing site?
Our code audit delivers a full report within 24 hours. For JavaScript landing page / marketing site projects, we check security, architecture, performance, and deployment readiness across all JavaScript-specific patterns. Fixes are scoped separately with a fixed quote.
Related resources
JavaScript by Use Case
Landing Page / Marketing Site by Technology
Need help with your JavaScript landing page / marketing site?
Tell us about your project. We'll respond within 24 hours with a clear plan and fixed quote.