Foglift vs Google Lighthouse
Lighthouse is the deeper developer diagnostic for lab performance and page quality. Foglift is the broader audit-to-answer workflow for AI Readiness, site health, AI Visibility, prioritized fixes, crawler activity, and referrals.
The short answer
Choose Foglift when you want one free baseline across AI Readiness, SEO, performance, security, and accessibility, followed by a path to five-engine monitoring and developer workflows from $49 per month. Choose Lighthouse when the immediate job is deep lab-performance diagnosis, trace evidence, local or authenticated testing, or CI automation. The strongest workflow starts broad with Foglift, then opens Lighthouse for the performance issues that need engineering detail.
Feature-by-feature comparison
This comparison separates readiness evidence, answer outcomes, observed crawler activity, and real referrals. A passing audit or crawler fetch is not proof of an AI citation.
| Capability | Foglift | Google Lighthouse |
|---|---|---|
| Best starting point | Unlimited single-page Technical Audits at $0, with no signup or card | Free open-source audit in Chrome, PageSpeed Insights, CLI, Node, or CI |
| Primary job | Find cross-discipline site gaps, monitor AI answers, rank fixes, and measure crawler and referral outcomes | Diagnose page quality, especially lab performance and developer-facing implementation issues |
| Audit scope | SEO, performance, security, accessibility, and a separate AI Readiness result | Performance, accessibility, best practices, SEO, and experimental Agentic Browsing |
| AI readiness | Eight dimensions covering structure, evidence, entities, content, and crawler access | Experimental deterministic checks for WebMCP, agent accessibility, stability, and llms.txt |
| Performance evidence | Performance score and prioritized issue summary inside a broader Technical Audit | Weighted lab metrics, traces, diagnostics, opportunities, and run-level detail |
| AI answer monitoring | Active-use weekly Perplexity on Free; five engines from the $49/mo Launch plan | Does not run tracked prompts or measure brand mentions, citations, sentiment, or share of voice |
| Crawler and referral evidence | Sensor separates crawler purpose from recognized human visits arriving through AI answers | Outside the Lighthouse audit workflow |
| Full-site coverage | Launch+: up to 100 selected pages, automatic weekly coverage, and seven-day manual availability | A page audit; larger programmes require Lighthouse CLI, Node, or CI orchestration |
| Developer workflow | REST API, CLI, hosted MCP, webhooks, and batch scanning start on Launch | DevTools, CLI, Node module, Lighthouse CI, plugins, and report JSON |
Where Foglift goes further
The Technical Audit is the first layer, not the whole product. It checks five reported dimensions and gives AI Readiness its own eight-dimension result. Paid AI Visibility monitoring then tests buyer questions across ChatGPT, Claude, Perplexity, Gemini, and Google AI Overview. Recommendations rank the next fix, while Sensor records crawler purpose and recognized human referrals separately.
- $0 audit: unlimited single-page Technical Audits without signup or a credit card through the public audit route.
- $49 Launch: five-engine monitoring, full-site audits, API, CLI, hosted MCP, webhooks, and batch scanning; the current limits are listed on pricing.
- Evidence boundaries: the AI Visibility scoring method keeps readiness, answer citations, crawler fetches, and referrals distinct.
- Improvement loop: technical and answer evidence feeds prioritized recommendations and post-fix verification.
- Developer access: the developer hub documents API, CLI, and MCP entry points.
Where Lighthouse goes deeper
Google documents Lighthouse as an open-source automated tool for performance, accessibility, best practices, and SEO. It runs in Chrome DevTools, from the command line, as a Node module, through PageSpeed Insights, or in CI. Its performance score is a weighted lab result built from First Contentful Paint, Speed Index, Largest Contentful Paint, Total Blocking Time, and Cumulative Layout Shift. Google also warns that the score can fluctuate with devices, routing, extensions, ads, and experiments.
Agentic Browsing is readiness, not visibility
Lighthouse's experimental Agentic Browsing category requires Chrome 150 or later. It uses deterministic checks for WebMCP integration, agent-focused accessibility, layout stability, and llms.txt discoverability. It reports a pass ratio instead of a weighted 0 to 100 score. That is useful developer evidence, but it does not query AI engines or measure brand mentions, answer citations, sentiment, competitors, share of voice, or human referral visits.
Which tool should you choose?
Choose Foglift when...
- You need a broad audit without installing a developer tool.
- You need AI Readiness kept separate from actual answer outcomes.
- You want to monitor five AI engines and compare competitors.
- You need prioritized recommendations after the diagnosis.
- You need crawler, citation, and referral evidence kept distinct.
- You want API, CLI, and hosted MCP access from $49 per month.
Choose Lighthouse when...
- You need the deepest lab-performance metrics and diagnostics.
- You need traces and opportunities for an engineering investigation.
- You want to test local, authenticated, or pre-release pages.
- You need custom configuration through CLI or Node.
- You want Lighthouse CI to catch page-quality regressions.
- You are testing experimental WebMCP and agent-interaction readiness.
Sources and review boundary
Google product facts were checked against current first-party documentation on September 19, 2026. Foglift product facts use the current public plan and capability contract.
- Google Chrome for Developers: Introduction to Lighthouse, audit categories, execution methods, CI, plugins, and report sharing.
- Google Chrome for Developers: Lighthouse performance scoring, metric weights, score distributions, and variability.
- Google Chrome for Developers: Agentic Browsing scoring, Chrome 150+, pass-ratio scoring, and deterministic audit scope.
- Google Chrome for Developers: WebMCP, proposed standard and origin-trial boundary.
Last reviewed: September 19, 2026. Pricing and experimental browser features can change; verify linked first-party pages before purchase or implementation.
Frequently asked questions
What is the main difference between Foglift and Google Lighthouse?
Lighthouse is a developer diagnostic for page quality, with deep lab-performance evidence and an experimental Agentic Browsing category. Foglift is a broader audit-to-answer workflow: unlimited single-page Technical Audits cover AI Readiness, SEO, performance, security, and accessibility, while paid monitoring measures answer outcomes across five AI engines.
Does Foglift replace Google Lighthouse?
No. Start with Foglift when you need one broad baseline and a path into AI Visibility monitoring. Open Lighthouse when a performance issue needs metric-level diagnosis, trace evidence, custom configuration, or CI automation. The tools answer different questions and work well together.
Does Lighthouse measure AI search visibility?
No. Lighthouse's experimental Agentic Browsing category checks technical readiness for machine interaction. It does not query ChatGPT, Claude, Perplexity, Gemini, or Google AI Overview, and it does not measure brand mentions, answer citations, sentiment, competitors, or share of voice. Foglift measures those outcomes on Launch and higher plans.
What does Foglift's AI Readiness analysis measure?
Foglift evaluates structured data richness, heading clarity, FAQ quality, entity identity, content depth, citation formatting, topical authority, and AI crawler access. These dimensions measure page readiness. They do not guarantee that an AI engine will mention or cite a brand, which is why answer monitoring remains a separate evidence layer.
Are Foglift and Lighthouse both free?
Yes, for different jobs. Foglift offers unlimited single-page Technical Audits at $0 without signup or a credit card. Lighthouse is open source and can run in Chrome DevTools, PageSpeed Insights, from the command line, or as a Node module. Foglift's five-engine monitoring and developer access start on Launch at $49 per month.
Which audit should I run first?
Run Foglift first when you need a broad, no-install baseline across site health and AI Readiness. Follow with Lighthouse when the performance result needs deeper diagnostics. If the business question is whether AI engines mention, cite, or send visitors to the brand, use Foglift's monitoring and Sensor evidence rather than either readiness score alone.
Continue the comparison
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