Guard scans the pages that matter to your business on a fixed schedule — rendering each one like a real browser, then running this full suite of 33 automated checks against it. Every test is purpose-built to catch one specific pattern of failure: a blank render, a dropped CTA, a broken canonical, a slow load — the kinds of issues that still return a 200 OK while quietly costing you traffic, conversions, and trust.
33 checks across 8 categories, each with a plain-English explanation of what it catches, why it happens, how to fix it, and what it costs you when it breaks.
Alongside the 33 checks below, every monitored page also gets these core features — so you get the complete picture of page health, performance, and search visibility in one place.
Performance, Accessibility, Best Practices & SEO tracked per page, per scan — so you see trends, not just snapshots.
robots.txt, sitemap.xml, llms.txt and favicons — the files crawlers depend on, checked on every scan cycle.
Plain-English summaries of wins, risks and prioritized next actions — no dashboards to interpret.
Clicks, impressions, rankings and CTR tied directly to Guard alerts and Lighthouse scores.
Surface high-value pages Google hasn't found yet, then promote them into Guard monitoring.
Monitoring, alerting, and protection for your most important pages.
The inner ring is each category; the outer ring is every individual test. Click a slice — or a category below — to filter the full list.
Showing 33 tests
Is the page even reachable?
| Test | Description | Signal | Severity | Build | |
|---|---|---|---|---|---|
| TLS Certificate Expiring Soon | TLS certificate expires within 14 days If not fixed, users will soon see security errors and be unable to access the site. Search engines may also stop crawling it, causing traffic to drop. | Certificate expiry | Warn | Easy to fix | |
| HTTP Status Failure | HTTP 500+, timeout, or DNS failure This page is effectively down. Users cannot access it, and search engines may remove it from results if the issue persists. This can lead to immediate traffic loss and broken user journeys. | HTTP status failure | Fail | Easy to fix | |
| Redirect Loop | Same URL redirect or redirect chain >3 hops Users will be unable to access the page, often seeing browser errors. Search engines may stop crawling the page entirely, which can remove it from search results. | Redirect loop | Fail | Easy to fix | |
| Redirect To Homepage | Non-root page redirects to homepage Users expecting this page will be confused or frustrated when redirected. Search engines may treat the page as non-existent, reducing visibility for that URL. | Redirect to homepage | Warn | Easy to fix | |
| TLS Certificate Failure | SSL handshake failure or invalid certificate Users may see security warnings or be blocked entirely from accessing the site. Search engines may avoid crawling the page, leading to severe traffic loss. | TLS failure | Fail | Medium effort | |
| Unexpected 4xx Error | Non-login page returns 4xx status Users and search engines will see this page as unavailable. This can reduce trust, break navigation flows, and cause search engines to stop indexing the page over time. | Unexpected 4xx | Warn | Easy to fix |
Did the page actually render?
| Test | Description | Signal | Severity | Build | |
|---|---|---|---|---|---|
| Blank Page Detected | HTML size <1KB or visible text extremely low Users and search engines will see little or no content. This can lead to immediate traffic loss, poor engagement, and potential deindexing. | Blank page | Fail | Easy to fix | |
| Critical Bundle Failure | Main JS or CSS bundle fails to load The page may not render at all, leaving users with a broken experience. This can result in immediate drop-offs and negatively impact search engine indexing. | Critical bundle failure | Fail | Medium effort | |
| High Resource Error Rate | More than 10% network resource failures Parts of the page may be broken or missing, leading to poor user experience. This can reduce trust, engagement, and conversion rates. | High resource error rate | Warn | Medium effort | |
| JavaScript Crash Detected | Page error or fatal console error detected Parts of the page may not function or render correctly. This can break user interactions and reduce conversions, while also impacting SEO if content fails to load. | JavaScript crash | Warn | Medium effort | |
| Script Shell Only | DOM mostly scripts with little rendered content Users and search engines may see an empty or unusable page. This can lead to lost traffic, poor SEO performance, and broken user flows. | Script shell only | Fail | Medium effort |
Did the content silently change?
| Test | Description | Signal | Severity | Build | |
|---|---|---|---|---|---|
| Critical DOM Selector Missing | User defined DOM selector not found Key parts of the page may be missing, leading to broken layouts or functionality. This negatively impacts user experience and engagement. | Critical selector missing | Major alert | Medium effort | |
| H1 Heading Removed | Primary H1 heading removed from page The page structure becomes less clear to both users and search engines. This can reduce readability and weaken SEO relevance signals. | H1 removed | Alert | Easy to fix | |
| Major DOM Drop | DOM node count drops more than 50% compared to baseline Large portions of the page are missing, which can confuse users and remove important content. This can severely impact both SEO visibility and user trust. | Major DOM drop | Major alert | Medium effort | |
| Major Text Content Drop | Visible text drops more than 40% compared to baseline Search engines rely on page content to understand relevance. Reduced content can lower rankings and make the page less useful to users. | Major text drop | Major alert | Medium effort | |
| Title Tag Removed | HTML <title> element missing Search engines rely on the title tag to understand and rank the page. Missing titles can reduce visibility and make search results less compelling to users. | Title removed | Alert | Easy to fix |
Are your SEO & AI signals intact?
| Test | Description | Signal | Severity | Build | |
|---|---|---|---|---|---|
| Canonical URL Changed | Canonical tag target changed unexpectedly Search engines may index the wrong version of the page or split ranking signals. This can reduce visibility and cause SEO confusion. | Canonical changed | Alert | Easy to fix | |
| Mixed Content Detected | HTTPS page loads HTTP resources Browsers may block insecure resources or show warnings. This reduces user trust and can break parts of the page experience. | Mixed content | Warn | Easy to fix | |
| Noindex Tag Added | Robots meta tag adds noindex This page will be removed from search engine results. Any existing SEO traffic to this page will drop to zero if the issue is not corrected. | Noindex added | Major alert | Easy to fix | |
| OpenGraph Tags Removed | Open Graph tags removed from page When shared on social platforms, this page may show poor or broken previews. This can reduce click-through rates and limit viral or referral traffic. | OG removed | Warn | Easy to fix | |
| Sitemap Invalid or Malformed | Sitemap XML is invalid, malformed, or not parsable Search engines rely on sitemaps to discover and crawl your pages. If the sitemap is invalid, pages may not be discovered or re-crawled efficiently. Over time, this can reduce indexing coverage and negatively impact search visibility, especially for new or recently updated pages. | Sitemap malformed | Warn | Easy to fix | |
| Sitemap Removed | Page missing from sitemap or sitemap invalid Search engines may have difficulty discovering or re-crawling this page. Over time, this can reduce indexing and visibility. | Sitemap removed | Warn | Medium effort | |
| Structured Data Removed | Structured schema markup missing or invalid The page may lose enhanced search features like rich snippets. This can reduce visibility and click-through rates from search results. | Structured data removed | Warn | Medium effort |
Is the page fast enough?
| Test | Description | Signal | Severity | Build | |
|---|---|---|---|---|---|
| Large HTML Size Jump | HTML size increases more than 50% compared to baseline Heavier pages load slower, which can hurt user experience and performance metrics. This may reduce engagement and negatively impact search rankings. | Large HTML size jump | Warn | Easy to fix | |
| Severe Slow Page Load | Page load >8 seconds total Users are likely to abandon the page before it loads. This directly impacts conversions and engagement, and can negatively affect search rankings. | Severe slow load | Major alert | Easy to fix | |
| Slow Response Time | Response time exceeds baseline or >5 seconds Users will experience delays, increasing bounce rates. Search engines factor performance into rankings, so slower pages may rank lower over time. | Slow response | Warn | Easy to fix | |
| TTFB Spike Detected | Time to first byte more than 2x baseline Slower initial response times degrade user experience and can impact search rankings. This may also signal deeper infrastructure issues affecting reliability. | TTFB spike | Warn | Medium effort |
Did a third party break you?
| Test | Description | Signal | Severity | Build | |
|---|---|---|---|---|---|
| Third Party Dependency Failure | External CDN or script dependency fails to load Critical functionality (payments, analytics, integrations) may break. This can directly impact revenue, tracking, and overall user experience. | 3rd party failure | Major alert | Medium effort | |
| Core Web Vitals Regression | LCP/CLS/INP regress beyond threshold Poor performance metrics can lower search rankings and frustrate users. This can reduce traffic, engagement, and conversions. | Core Web Vitals regression | Major alert | Hard to fix | |
| Unexpected Script Added | New external script detected on page Additional scripts can slow down the page or introduce instability. This may impact performance, user trust, and overall experience. | Unexpected script | Warn | Medium effort |
Can users actually convert?
| Test | Description | Signal | Severity | Build | |
|---|---|---|---|---|---|
| Primary CTA or Form Failure | Primary CTA or form flow broken Users cannot complete key actions like signup or checkout. This directly impacts conversions, revenue, and overall business performance. | CTA or form failure | Major alert | Hard to fix | |
| Pricing Page Conversion Integrity | Detects pricing-like pages where visible price or conversion CTA signals are missing, and warns on malformed JSON-LD found on the pricing page. A broken pricing page can reduce conversions and also makes it harder for search engines, AI systems, and users to understand the offer, price, and purchase path. | Pricing page conversion integrity | Alert | Medium effort |
Is anything tampering with the page?
| Test | Description | Signal | Severity | Build | |
|---|---|---|---|---|---|
| Script Injection Detected | Unexpected injected script or DOM element detected This may indicate a security issue. It can compromise user trust, damage your brand, and potentially expose sensitive data. | Script injection detected | Major alert | Medium effort |
Add the pages that matter and Guard scans them every 30 minutes, compares against a baseline, and alerts you the moment any of these checks starts to fail.
Prefer a guided tour? See how Guard works.