Lighthouse measures your engine. Roasted critiques the whole car.
Lighthouse is the gold standard for Core Web Vitals and accessibility scoring. But it has zero opinion on your copy, your design quality, your trust signals, or why visitors leave without converting. Roasted is an AI-powered website roast that critiques your entire site across 8 pillars covering 15+ dimensions and attributes — from headline clarity to conversion funnel friction to social proof placement. Lighthouse tells you your engine runs. Roasted tells you nobody wants to get in the car. Here is the full comparison of these two website analysis tools.
Feature-by-feature comparison
Comparison based on publicly available information. Last updated March 2026.
Quick verdict
Google Lighthouse excels at what it was built for. Roasted covers the dimensions Google Lighthousedoesn't touch — design quality, copy effectiveness, trust signals, and conversion optimization. They're complementary tools, not competitors. Start with a free Roasted audit to see what you're missing.
Roasted vs Lighthouse: The Complete Deep Dive
What Lighthouse Actually Measures vs What Roasted Measures
Google Lighthouse audits websites across four core categories: Performance, Accessibility, Best Practices, and SEO. The performance category is its crown jewel — it runs a simulated page load in a throttled Chromium environment and produces precise metrics like Largest Contentful Paint, First Input Delay, Cumulative Layout Shift, and Time to Interactive. The accessibility audit checks for WCAG compliance issues like missing alt text, insufficient color contrast, and improper ARIA attributes. Best practices covers HTTPS usage, console errors, and deprecated APIs. The SEO audit checks for meta tags, crawlable links, and mobile viewport configuration.
Roasted takes a fundamentally different approach. Instead of running lab simulations, Roasted deploys AI-powered agents across more than 15 dimensions: design quality, copywriting effectiveness, trust and credibility signals, conversion optimization, speed and performance, mobile experience, SEO depth, security posture, accessibility compliance, social proof placement, network performance, and more. Each agent analyzes the page the way a real expert would — reading the headlines for clarity, evaluating the visual hierarchy for usability, checking whether trust elements like testimonials and security badges are present and well-positioned, and assessing whether the call-to-action language creates urgency or falls flat.
The key difference is scope versus depth. Lighthouse goes deep on the technical performance stack but has absolutely nothing to say about whether your homepage headline makes sense, whether your pricing page builds enough trust, or whether your CTA button color creates visual friction. Roasted covers the full spectrum of what makes a website succeed or fail in the real world — including the subjective, qualitative factors that no synthetic lab test can measure.
The Gap Between Performance Scores and Actual Conversion
One of the most dangerous misconceptions in web development is that a high Lighthouse score equals a successful website. Teams celebrate hitting 95 or 100 on all four Lighthouse categories and then wonder why their conversion rate is stuck at 0.5 percent. The truth is that Lighthouse measures technical health, not business effectiveness. A website can load in under one second, pass every accessibility check, and have perfect meta tags — and still utterly fail to convert visitors into customers because the copy is confusing, the design looks untrustworthy, or the call-to-action is buried below the fold.
This performance-conversion gap is where Roasted provides its highest value. Roasted does not care how many milliseconds your LCP takes if your above-the-fold content fails to communicate what your product does in the first five seconds. Roasted does not care that your images are properly lazy-loaded if your hero section uses a stock photo that screams "we could not be bothered to show our actual product." The metrics Lighthouse measures are necessary but nowhere near sufficient for a website that needs to generate revenue, capture leads, or build a brand.
Real conversion optimization requires evaluating the entire user experience holistically — from the emotional impact of the first visual impression to the clarity of the value proposition to the friction in the checkout or signup flow. Lighthouse cannot touch any of this. Roasted was built specifically to fill this gap, providing the kind of critique that used to require hiring an expensive conversion rate optimization consultant.
Why Developers Over-Rely on Lighthouse and What It Costs Them
Lighthouse has become the default "is my site good?" tool because it ships with every Chrome installation and produces a clean numeric score. Developers love numbers. A score of 94 feels tangible and measurable in a way that "your headline is unclear" does not. This creates a dangerous feedback loop: teams optimize obsessively for Lighthouse metrics because those are the metrics they can see, while ignoring the qualitative factors that actually determine whether the site achieves its goals.
The cost of this over-reliance is invisible but enormous. Teams spend weeks shaving 200 milliseconds off their LCP by implementing complex image optimization pipelines, code-splitting strategies, and edge caching — all worthwhile work — while their homepage still opens with "Welcome to Our Platform" as the headline and has no social proof above the fold. The performance improvements are real but the business impact is negligible because the site was never failing on performance. It was failing on persuasion, clarity, and trust.
Roasted breaks this cycle by giving teams a score across dimensions they were not measuring before. When a developer sees that their site scores an 85 on speed but a 42 on trust and a 55 on copy quality, it reframes the optimization conversation entirely. Suddenly the highest-leverage improvement is not another performance tweak — it is rewriting the headline, adding customer testimonials, or making the pricing page less confusing. That shift in priorities is often worth more than any Lighthouse optimization could ever deliver.
How Roasted Complements Lighthouse in a Professional Workflow
The most effective website quality strategy uses both tools at different stages of the development lifecycle. Lighthouse belongs in your CI/CD pipeline, running on every pull request to catch performance regressions, accessibility violations, and SEO misconfigurations before they reach production. It excels as a technical quality gate — an automated safety net that prevents your bundle size from ballooning or your Core Web Vitals from degrading. This is where Lighthouse truly shines, and Roasted does not attempt to replace it.
Roasted belongs at the strategic inflection points: before a major launch, after a redesign, during a quarterly site health review, or when you are preparing a client deliverable. It provides the kind of high-level, holistic critique that helps teams make design and content decisions — not just engineering decisions. A Roasted audit before launch might catch that your new landing page has three competing CTAs, your trust section is buried on mobile, or your checkout page asks for too much information upfront. These are the issues that directly impact revenue and that no automated performance test will ever detect.
Together, the two tools create a comprehensive quality assurance system. Lighthouse guards the technical floor — ensuring your site is fast, accessible, and well-structured. Roasted raises the strategic ceiling — ensuring your site is persuasive, trustworthy, and optimized for the human beings who actually use it. Running one without the other leaves a massive blind spot in your quality process.
Real Scenarios Where Lighthouse Passes But the Site Fails Users
Consider a SaaS startup that launches a new landing page. Lighthouse gives it a 98 performance score, 100 on accessibility, 100 on best practices, and 95 on SEO. The developers high-five. But the page converts at 0.3 percent because the headline says "Next-Generation Workflow Optimization Platform" — meaningless jargon that tells nobody what the product actually does. The subhead is a wall of text. The CTA says "Get Started" with no indication of whether that means signing up, starting a free trial, or scheduling a demo. Lighthouse sees none of this. Roasted's Copy Agent would flag every issue in thirty seconds.
Or take an ecommerce site that scores perfectly on Lighthouse but has a bounce rate north of 70 percent. The performance is great — images load fast, no layout shift, smooth scrolling. But the product pages have no customer reviews visible above the fold, the trust badges are tiny and positioned in the footer where nobody scrolls, and the "Add to Cart" button blends into the background because the color contrast is optimized for WCAG compliance but not for visual hierarchy. Lighthouse checks that the button is accessible. Roasted checks that anyone would actually want to click it.
A third common scenario involves agency client sites. The developer delivers a technically perfect site — all green scores in Lighthouse, fully responsive, blazing fast on every device. The client is initially thrilled, but three months later the site has generated zero leads. The problem was never technical. The site lacked a clear value proposition, had no lead capture above the fold, buried the contact form behind three clicks, and used stock photography that made a premium law firm look like a template site. Roasted catches these issues instantly because it evaluates the site the way a prospective customer would — not the way a browser rendering engine does.
Curious how your site stacks up?
🔥 Get your free roast — 30 seconds, no accountWhy Roasted goes beyond Lighthouse
Copy & messaging analysis
Lighthouse doesn't read your headlines. Roasted's Copy Agent flags weak CTAs, confused messaging, and low-clarity value props that tank conversion.
Design quality scoring
No tool before Roasted could tell you if your visual hierarchy is broken, your colors create friction, or your layout looks amateurish. Now one can.
Trust signal audit
Lighthouse won't notice you're missing a credibility section, reviews are buried, or your About page is one sentence. Roasted's Trust Agent does.
Conversion funnel review
High Lighthouse scores and zero conversions is a real problem. Roasted surfaces CTA placement issues, friction in your funnel, and missed revenue signals.
AI-native fix prompts
Every Roasted finding ships with a paste-ready prompt you can drop into Claude, ChatGPT, or Cursor. Lighthouse gives you raw metrics and leaves you to figure it out.
Shareable roast links
Share your roast with teammates, clients, or stakeholders. Lighthouse reports live in DevTools and die when you close the tab.
Pricing: Roasted vs Lighthouse
Lighthouse is completely free — it ships inside Chrome DevTools and costs nothing to run. Roasted offers a generous free tier plus paid plans that unlock dimensions of analysis Lighthouse can never provide, no matter how many times you run it.
🔥 Roasted
- Up to 3 full audits per day
- All 8 pillars, 15+ analysis dimensions included
- AI-generated fix prompts on every finding
- Shareable results link for every audit
- Works in any browser — no extension needed
- Unlimited audits — no daily cap
- Multi-page crawl (audit entire sites, not just single pages)
- PDF export for client-ready reports
- Score history and trend tracking over time
- Priority processing during peak hours
- Everything in Plus
- White-label reports with your agency branding
- Full API access for custom integrations
- Priority support with faster response times
- Bulk audit scheduling for large site portfolios
Google Lighthouse
- Performance scoring with Core Web Vitals
- Accessibility audit (WCAG-based)
- Best practices checklist
- Basic SEO checks (meta tags, crawlability)
- Node CLI for CI/CD integration
Lighthouse is unbeatable on price for what it does — technical performance and accessibility auditing at zero cost. But it only covers four dimensions. Roasted's free tier already gives you more analysis depth than Lighthouse across 15 or more dimensions. The paid tiers add workflow features — unlimited audits, multi-page crawl, PDF export, white-label branding, and API access — that transform Roasted from a spot-check tool into a professional-grade audit platform. You are not paying for what Lighthouse already gives you for free. You are paying for the dimensions Lighthouse will never cover.
When to Use Lighthouse vs When to Use Roasted
Use Google Lighthouse when you need to...
CI/CD performance gates
Lighthouse's Node CLI integrates directly into your build pipeline. Set performance budgets and fail builds that regress on Core Web Vitals. This automated guardrail is Lighthouse's killer feature and something Roasted does not yet offer.
Core Web Vitals debugging
When you need to diagnose exactly why your LCP is 4.2 seconds, Lighthouse's detailed timing breakdown, filmstrip view, and treemap visualization give you the precise technical data to pinpoint the bottleneck.
Accessibility compliance audits
Lighthouse's accessibility audit is thorough and standards-based. If you need to verify WCAG 2.1 AA compliance for legal or regulatory reasons, Lighthouse provides the structured, citation-backed report you need.
PWA readiness checks
Building a Progressive Web App? Lighthouse validates your service worker registration, web app manifest, offline functionality, and installability criteria — a specialized checklist no other tool matches.
Performance budget enforcement
Lighthouse lets you define budgets for JavaScript size, image weight, third-party scripts, and total transfer size, then flags violations. Essential for teams that need to keep their bundle lean over time.
Use Roasted when you need to...
Holistic site quality audit before launch
Before pushing a new site or major redesign live, run Roasted to catch the issues that technical tests miss — unclear messaging, missing trust signals, weak CTAs, poor visual hierarchy, and conversion friction points.
Copy and messaging review
Roasted's Copy Agent reads your headlines, subheads, CTAs, and body copy like a human would. It flags jargon-heavy language, unclear value propositions, and calls-to-action that fail to create urgency or clarity.
Design critique and visual quality assessment
Get AI-powered feedback on your visual hierarchy, color usage, typography choices, whitespace balance, and overall design polish. No other automated tool provides this level of design-focused analysis.
Conversion optimization analysis
Roasted evaluates your funnel from landing to action — checking CTA placement, form friction, pricing page clarity, social proof positioning, and the dozen small details that determine whether visitors convert or bounce.
Client-facing audit reports
Generate shareable links or branded PDF reports that non-technical clients can actually understand. Roasted explains issues in plain English with specific fix recommendations, not technical jargon and raw performance numbers.
The best approach? Use both.
The most effective teams use Lighthouse as an automated technical guardrail in their CI/CD pipeline — catching performance regressions and accessibility violations on every commit — while using Roasted at strategic checkpoints like pre-launch reviews, quarterly site health audits, and client deliverables. Lighthouse prevents technical quality from slipping. Roasted ensures the site is actually persuasive, trustworthy, and optimized for real humans. One protects the floor; the other raises the ceiling. Skip either one and you are leaving significant quality gaps in your process.
5 Unique Advantages Roasted Has Over Lighthouse
Covers 8 pillars (15+ dimensions and attributes) vs Lighthouse's 4
Lighthouse audits performance, accessibility, best practices, and basic SEO. Roasted covers all of those plus design quality, copywriting effectiveness, trust and credibility signals, conversion optimization, mobile UX depth, security posture, accessibility, social proof, network analysis, and more. That means Roasted catches entire categories of issues — weak headlines, missing social proof, buried CTAs, untrustworthy design patterns — that Lighthouse has no mechanism to detect. The additional dimensions are not nice-to-haves; they are the factors that most directly determine whether your site achieves its business goals.
AI-generated fix prompts you can paste directly into your tools
Every issue Roasted identifies comes with a paste-ready prompt designed for AI coding assistants like Claude, ChatGPT, or Cursor. Instead of reading a vague recommendation and figuring out how to implement it yourself, you copy the prompt, paste it into your AI tool of choice, and get working code or copy in seconds. Lighthouse gives you raw metrics and technical descriptions that assume significant developer expertise to interpret and act on. Roasted closes the gap between "here is the problem" and "here is the solution" in a way no other audit tool does.
Shareable results that live beyond your browser session
When you run a Roasted audit, you get a permanent URL you can share with anyone — teammates, clients, stakeholders, your Twitter followers. They see the full audit results instantly in any browser without needing Chrome, DevTools, or any special setup. Lighthouse results exist only in the DevTools panel of the Chrome tab that ran the audit. Close that tab and the results are gone. You can manually export JSON or HTML, but sharing requires emailing files or self-hosting the report. Roasted makes collaboration effortless by default.
Design and copy analysis that no performance tool can replicate
Lighthouse was built to measure what browsers can measure programmatically — load times, DOM structure, ARIA attributes, HTTP headers. It cannot evaluate whether your hero image makes your brand look professional or cheap, whether your headline communicates your value proposition clearly, whether your color palette creates the right emotional response, or whether your pricing page layout builds enough trust for visitors to enter their credit card. Roasted uses AI to evaluate these subjective but critically important factors, providing the kind of feedback that previously required hiring a human designer, copywriter, or conversion consultant.
Non-technical language that everyone on your team can understand
Lighthouse reports are written for developers. Terms like "Largest Contentful Paint," "Total Blocking Time," "render-blocking resources," and "unused JavaScript" mean nothing to your marketing team, your CEO, or your clients. Roasted explains every finding in plain English that anyone can understand: "Your headline does not tell visitors what your product does," "Your pricing page has no customer testimonials," "Your mobile menu takes three taps to reach the sign-up button." This makes Roasted the audit tool you can actually share across your entire organization without needing a developer to translate the results.
See for yourself in 30 seconds
Paste any URL and get a brutally honest AI audit across 8 dimensions. No account needed.
Get my free roast →Frequently asked questions
Is Roasted a replacement for Google Lighthouse?
They are complementary tools that serve very different purposes. Lighthouse is the gold standard for lab-based Core Web Vitals measurement, bundle analysis, accessibility auditing, and CI/CD performance gating. Roasted covers the qualitative dimensions Lighthouse completely ignores: design quality, copywriting effectiveness, trust signals, and conversion optimization. Most high-performing teams run Lighthouse in their CI pipeline for technical performance gates and then use Roasted before every major launch or redesign to catch the qualitative issues that directly impact revenue. You do not need to choose one or the other — you need both.
Does Roasted measure Core Web Vitals like Lighthouse does?
Yes, but differently. Roasted's Speed Agent evaluates performance signals including Largest Contentful Paint, bundle weight, render-blocking resources, image optimization, and server response time. However, Roasted is not a synthetic lab test — it does not simulate throttled network conditions or generate the precise millisecond-level timing data that Lighthouse produces. Instead, Roasted focuses on the actionable performance problems that actually slow down real users and provides plain-English explanations with paste-ready fix prompts. If you need exact LCP numbers in a controlled environment, Lighthouse is the right tool. If you need to understand why your site feels slow and what to fix first, Roasted gives you a clearer path forward.
Why would I pay for Roasted when Lighthouse is completely free?
Lighthouse is free because it only covers technical performance metrics that browsers already collect. Roasted's value comes from AI-powered analysis across dimensions that no free tool touches — copywriting quality, visual design critique, trust and credibility signals, conversion funnel optimization, and more. The free tier gives you three full audits per day, which is enough for most individual projects. The paid tiers add unlimited audits, multi-page crawl, PDF export, white-label reports, and API access — features designed for professionals and agencies who need to audit client sites at scale. Think of it this way: Lighthouse tells you your car engine runs fine. Roasted tells you the paint is peeling, the interior smells weird, and nobody wants to ride in it.
Can I share Roasted results with clients like I can with Lighthouse reports?
This is one of the biggest differences. Lighthouse results are trapped inside Chrome DevTools — when you close the tab, the report is gone. You can manually export a JSON or HTML file, but sharing it requires attaching files to emails or hosting it yourself. Roasted generates a permanent shareable URL for every audit. You can send the link to clients, teammates, or stakeholders and they see the full roast instantly in their browser — no DevTools required, no file downloads, no Chrome dependency. Plus and Pro subscribers can also export PDF reports with custom branding for professional client presentations.
How do Roasted and Lighthouse compare for SEO auditing specifically?
Lighthouse performs basic SEO checks — it verifies that you have a title tag, meta description, robots.txt, and proper heading hierarchy. These are table-stakes validations that most modern frameworks handle automatically. Roasted's SEO Agent goes significantly deeper: it analyzes keyword relevance, content structure for search intent, internal linking quality, schema markup opportunities, image alt text effectiveness, and how well your above-the-fold content communicates your core value proposition to both search engines and human visitors. If you only need to confirm that your meta tags exist, Lighthouse is sufficient. If you need to understand why your page is not ranking despite having all the technical boxes checked, Roasted provides the qualitative SEO insights that actually move the needle.
What is a website roast and how is it different from a Lighthouse audit?
A website roast is Roasted's signature approach to website analysis. Instead of producing a clinical spreadsheet of technical metrics like Lighthouse does, Roasted delivers an AI-powered narrative critique — a brutally honest, personality-driven assessment of your site across 8 pillars spanning 15+ quality dimensions. The roast format evaluates everything a real visitor experiences: is your headline compelling or confusing? Does your design build trust or undermine it? Is your call-to-action obvious or buried? Are your trust signals visible or missing entirely? Every finding comes with a plain-English explanation and a paste-ready fix prompt for AI coding tools. It is the difference between a score on a dashboard and a senior consultant sitting next to you, pointing at your screen, and telling you exactly what to fix and why.