Facts checked September 14, 2026
Foglift vs Nibbler
Nibbler is the faster free snapshot: a 60-second SEO audit that samples up to five pages. Foglift is the stronger operating layer when you need unlimited single-page Technical Audits, separate eight-dimension AI Readiness, recurring AI answer monitoring, prioritized fixes, and developer access. Five-engine monitoring, REST API, CLI, and MCP start at $49 per month.
The short answer
Choose Foglift for diagnosis through measurement
Run an unlimited $0 Technical Audit for one URL, inspect the separate AI Readiness evidence, and export a PDF. Recommendations keep the audit-to-improvement workflow available on every plan. Launch adds daily monitoring across ChatGPT, Claude, Perplexity, Gemini, and Google AI Overview, plus weekly full-site audits, REST API, CLI, hosted MCP, webhooks, and batch scanning.
Choose Nibbler for a quick five-page sample
Enter a public URL and get a no-account SEO snapshot across as many as five pages. The current report compares eight free tests and points agencies toward Insites for larger audits, white-label reporting, competitor comparisons, and batch testing.
- Fast, public SEO snapshot
- Up to five sampled pages
- Simple entry point with no account
Free Technical Audit comparison
| Decision | Foglift | Nibbler |
|---|---|---|
| Free starting point | Unlimited single-page Technical Audits at $0, with no credit card | Free 60-second SEO audit with no account required |
| Pages per audit | One URL for the free audit; Launch adds weekly full-site coverage of up to 100 selected pages | Samples up to five pages in the free report |
| Audit scope | SEO, performance, security, accessibility, plus a separate AI Readiness result | Eight free-report tests; its five-page method covers SEO and broader web-presence signals |
| AI Readiness | Eight inspectable dimensions for page structure, evidence, entities, and crawler access | No dedicated AI-readiness assessment is presented in the current free report |
| AI answer monitoring | Active-use weekly Perplexity on Free; five engines from Launch | The free report is a website test, without tracked prompts or answer citations |
| Crawler and referral evidence | Sensor separates crawler requests from human visits through AI answer links | Outside the current free-report workflow |
| Performance | PageSpeed category evidence plus local page checks inside the Technical Audit | A quick experience-oriented website score |
| Shareable output | Shareable saved result and branded PDF export | Public result page with browser print-to-PDF guidance |
| Developer workflow | REST API, CLI, hosted MCP, webhooks, and batch scanning start on Launch | No API, CLI, or MCP surface is presented in the free report |
| Paid operating layer | $49/month Launch adds daily five-engine monitoring and developer access | The report promotes a separate Insites account for larger audits and agency workflows |
Decision shorthand
- Choose Foglift
- Your audit needs to lead into AI Readiness, prioritized fixes, recurring answer monitoring, crawler and referral measurement, or API, CLI, and MCP delivery workflows.
- Choose Nibbler
- You want a fast, no-account SEO snapshot that samples up to five pages and you do not need ongoing AI answer measurement in the same product.
Where the five-page sample helps
Nibbler is useful when one homepage would hide an inconsistent site. Its five-page sample can expose a problem that appears on a category or detail page while keeping the test fast and free. Silktide documents that sampling model as part of Nibbler's design.
Foglift separates the two audit jobs. The public Technical Audit goes deeper on one URL and remains unlimited. Launch users also receive automatic weekly full-site coverage, can run a manual full-site audit once every seven days, and keep completed findings for up to 100 selected pages in Technical History.
What AI Readiness adds to a website test
Structured-data richness
Checks whether machine-readable markup carries useful page context.
Heading clarity
Tests whether the content hierarchy exposes a clear answer path.
FAQ quality
Separates useful question-and-answer structure from decorative FAQ labels.
Entity identity
Looks for clear organization, person, and product identity signals.
Content depth
Measures whether the page contains enough substantive text for the job it claims.
Citation formatting
Looks for sourced, attributable claims that can be extracted safely.
Topical authority
Checks whether the page has supporting topic coverage and internal context.
AI crawler access
Reports whether named search, training, and live-fetch agents can access the page.
The evidence boundary
A Technical Audit can show whether a page is technically accessible and easy to extract. It cannot prove that an AI engine cited the page or sent a visitor. Foglift keeps those outcomes separate: monitored answers provide mention and citation evidence, Sensor logs crawler requests, and referral analytics record recognized human visits from AI answer links.
That separation is the practical reason to choose the larger workflow. Nibbler remains a useful fast audit.Foglift is built for teams that need to diagnose the page, ship the fix, and measure the answer-level and traffic outcome afterward.
Primary sources and product specifications
- Nibbler: current free website test for the free 60-second audit and no-account entry point.
- Silktide: Nibbler history and five-page method for the sampling model and the original accessibility, SEO, and social-networking scope.
- Foglift Technical Audit specification for the single-page, full-site, report, PDF, plan, and history boundaries.
- Foglift AI Visibility scoring methodology for the separate monitored-answer evidence and scoring contract.
Start with the deeper free audit
Run a Foglift Technical Audit when the decision includes SEO, performance, security, accessibility, and AI Readiness. The single-page audit is unlimited at $0 and produces a shareable result with PDF export.
Run a Free Technical AuditFrequently asked questions
What is the main difference between Foglift and Nibbler?
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Nibbler offers a quick multi-page crawl with simple 0-10 scoring. Foglift provides deeper single-page analysis with AI search readiness scoring, security headers audit, performance metrics, and actionable AI recommendations.
Is Foglift more affordable than Nibbler?
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Foglift offers free unlimited Technical Audits with no credit card required, and paid monitoring plans start at $49/mo. Nibbler starts at Free (no signup required). Foglift includes SEO analysis and AI Readiness scoring; API keys, CLI, and MCP access are available on Launch, Growth, and Enterprise plans.
Do Foglift and Nibbler both offer free plans?
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Yes, both tools offer free options. Foglift provides free unlimited Technical Audits with no signup and no credit card, including full SEO and AI Readiness scoring. Nibbler starts at Free (no signup required). Check each tool's website for current plan details.
Which is better for SEO and AI search optimization: Foglift or Nibbler?
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Foglift combines traditional SEO auditing with AI search readiness scoring (GEO) in a single tool — something most competitors, including Nibbler, do not offer at this price point. If you need to understand how AI search engines like ChatGPT, Perplexity, and Gemini see your website, Foglift is purpose-built for that.
When should I choose Nibbler over Foglift?
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Consider Nibbler if you need: quick multi-page crawl (up to 5 pages tested at once), social media presence check across platforms, technology stack detection. Nibbler is a strong choice for those specific use cases. Foglift is the better fit if you want unlimited single-page Technical Audits, combined SEO + AI Readiness analysis, or developer tools on Launch+ plans (API, CLI, MCP).
How we compare
These sources explain why the comparison separates AI-answer visibility from search rank, checks results by engine, and dates product evidence. They do not determine feature or pricing verdicts and do not establish universal ranking factors.
- Aggarwal et al., “GEO: Generative Engine Optimization,” KDD 2024. The 10,000-query GEO-Bench found that tested textual interventions including citations, quotations, and statistics could improve source visibility by up to 40 percent, with results varying by domain. The study did not test JSON-LD or Google AI Overviews.
- SE Ranking, “What actually drives AI citations,” current first-party study summary. The analysis covers 129,000 domains and 216,000 pages for ChatGPT plus 295,000 domains and 2.3 million pages for AI Mode. Referring domains ranked first for ChatGPT; organic traffic ranked first for AI Mode.
- Chatoptic, “SEO ≠ GEO: Only 62% Overlap Between Google Ranking and ChatGPT Visibility,” 2025. Across 1,000 queries, 15 brands, and five categories, Google top-10 position had a 0.034 correlation with ChatGPT mention order when browsing was on. The study measured mentions and order, not URL citations.
- Ahrefs, “AI Assistants Prefer to Cite Fresher Content,” 2025. Across 16.975 million cited URLs, AI-assistant citations skewed newer than organic results on average, while Google AI Overviews did not. Treat recency as an observational signal, not a causal score.
Feature and pricing data is verified against each tool's public website before comparison pages are refreshed.