Technical Health

Technical Health is the first and most heavily weighted layer of your Cassian Score™, accounting for 30% of the total. Cassian™ crawls your store's pages — up to your plan's page limit — and runs deterministic checks against the technical fundamentals that affect your store's search visibility, user experience, and reliability. These checks are instant, rules-based analysis — not AI-powered — which makes them fast, free, and completely consistent between scans.

A store can have beautiful design and excellent copy, and still have a low Technical Health score if the underlying structure is broken. This is the layer most likely to surface problems your customers are already experiencing — they just aren't telling you.

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What Cassian checks

Broken links

Link checking runs as its own scheduled feature (Cassian Sentinel™ Link & Media Health), separate from the scan crawl. It checks the links on a set number of pages per run, depending on your plan:

Broken-link results feed into your Technical Health score from the most recent completed link check — so your first-ever scan carries no link deductions until the first link check has run.

How severity is assigned:

• Broken internal links (404s on your own pages) — High
• Broken image or media files — Medium
• 5xx server errors — Medium
• Broken external links — Low
• Links returning 403 or blocked by bot protection are reported for information but carry no score deduction — they're usually the destination site blocking automated checks, not a real problem
• Deductions are capped at 50 issues per class, so one systemic problem can't obliterate the layer score

Where to fix: In Shopify, set up URL redirects at Online Store → Navigation → URL Redirects. For deleted pages or products, point the old URL to the most relevant active page.

Meta titles

Every page should have a single, descriptive meta title. Cassian flags:

• Missing or empty meta title (Critical) — The page has no title tag, or the tag is empty.
• Too short (Medium) — Titles under 10 characters. Aim for 50–60 characters to use the available space.
• Too long (Low) — Titles over 60 characters are truncated in search results, which can make them misleading.
• Multiple title tags (High) — More than one <title> tag on the same page, which leaves search engines to guess which one to use. (Cassian does not currently compare titles across different pages.)

Where to fix: In Shopify, the meta title for each page, product, or collection is set in the SEO section of the page editor. Look for the "Page title" field in the Search engine listing preview section.

Meta descriptions

Cassian flags pages with a missing or empty meta description (High severity). Length and cross-page uniqueness are not currently checked — the check is about presence.

Meta descriptions don't directly affect search rankings, but they affect click-through rate significantly. A well-written, unique description is one of the cheapest conversion improvements available.

Where to fix: In Shopify, set the meta description in the same SEO section as the meta title (Search engine listing preview → Description).

Schema markup

Structured data tells search engines — and increasingly AI shopping assistants — what's on your page in a machine-readable format. Cassian checks:

• Product schema — Every product page should have Product structured data. Missing Product schema is High severity; schema missing key fields (name, description, image, offers/price, brand, SKU) is Medium.
• Breadcrumb schema — Helps search engines understand your site hierarchy. Missing BreadcrumbList schema is Low severity.
• Organisation schema — Checked on your homepage. A homepage with no Organization, WebSite, or Store schema is High severity — this is how search engines and AI systems identify your business.

These schema findings are categorised under LLM Readiness, so look for them under the LLM Readiness filter on the Issues page. See the LLM Readiness feature page for full details.

Where to fix: Most Shopify themes include Product schema by default. Check by viewing page source and searching for "@type": "Product". If it's missing, add it via a theme customisation or a structured data app.

Image alt text

Every meaningful image on your site should have a descriptive alt text attribute. Cassian flags images that have no alt attribute at all. An explicit empty alt="" passes — that's the correct markup for decorative images. Tracking pixels and 1×1 images are ignored.

Alt text matters for two reasons: accessibility (screen readers use it to describe images to visually impaired users) and SEO (search engines use it to understand what an image shows, which is increasingly important for visual search).

Where to fix: In Shopify, add alt text to product images by clicking the image on the product edit page and selecting "Edit alt text". For theme images, edit via the theme customiser.

SSL and HTTPS

Cassian checks for page-level SSL issues — specifically mixed content, where an HTTPS page loads resources (images, scripts, stylesheets) over unencrypted HTTP. Mixed content triggers browser security warnings and can cause resources to fail loading entirely in modern browsers.

Where to fix: Check your theme for any hardcoded HTTP URLs in image src attributes or script tags. Third-party apps can also introduce mixed content — check your browser's developer console for mixed content warnings.

Canonical tags

A canonical tag tells search engines which version of a URL is the "official" one. Cassian flags missing canonicals — pages with no canonical tag, which can cause duplicate content issues if the same page is accessible at multiple URLs. Whether an existing canonical points to the right page is not currently validated.

Where to fix: Shopify automatically generates canonical tags for most page types. Custom themes or URL restructuring can introduce issues. Review the affected URLs listed in the Issues panel.

Robots meta tag

Cassian checks each page for a <meta name="robots"> tag and flags pages without one (Low severity, categorised under LLM Readiness). The tag isn't required, but it helps search engines and AI crawlers understand your indexing preferences.

Cassian does not currently validate your robots.txt file itself — Disallow rules aren't parsed or checked against your pages.

XML sitemap

Your XML sitemap is a roadmap for search engines — it tells them which pages exist and should be indexed. Cassian Sentinel™ Sitemap Health checks that:

• A sitemap exists (typically at yourstore.com/sitemap.xml)
• The sitemap parses as valid XML
• What changed — Cassian snapshots your sitemap URLs (up to your tier's limit) and diffs them between checks, so you're alerted when pages disappear from or flood into your sitemap unexpectedly

Where to fix: Shopify automatically generates a sitemap. If pages are missing, check that they're published (not draft status). Shopify's sitemap is at /sitemap.xml and cannot be customised directly, but unpublished content is excluded automatically.

Performance signals

During the crawl, Cassian runs static performance heuristics on each page's HTML:

• Render-blocking scripts — scripts in the head without defer or async
• Image dimensions — images without width/height attributes, which cause layout shift
• Lazy loading — below-the-fold images without loading="lazy"
• Responsive images — large images served without srcset
• Third-party scripts — an excessive number of external script domains
• Missing preconnect — third-party origins used without a preconnect hint

These are static observations from the page HTML — Cassian does not measure Core Web Vitals (LCP, CLS, INP) during the crawl. Measured performance data comes from the PageSpeed feature.

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How many pages does Cassian check?

The number of pages crawled per scan depends on your plan:

Cassian discovers pages from your XML sitemap plus the links on your homepage — it does not follow links hop-by-hop deeper into the site. From the discovered set, a fixed group of high-impact pages is always included first: your homepage, cart, checkout, account, search, collections index, products index, policy pages, and your first five product pages. The remaining budget is filled in discovery order.

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Where to see Technical Health results

• Issues page → filter by "Technical" category. All technical issues listed by severity.
• Scans page → click any scan → Technical Health section shows your score for that layer and the issues found.
• Dashboard overview → the Technical Health card shows your current layer score.

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Common questions

Does Cassian check every page on my store? It discovers pages from your sitemap and the links on your homepage, then crawls up to your tier's page limit. A fixed set of high-impact pages (homepage, cart, checkout, collections, products, policies, and your first five product pages) is always included first.

My store has tens of thousands of pages — will Cassian catch everything? Prime and Enterprise plans cover effectively unlimited pages. On Analyst, Protector, and Guardian plans, Cassian focuses on the most important pages. For comprehensive coverage of a very large catalogue, Prime is the appropriate tier.

What exactly is llms.txt and why does it matter? llms.txt is a markdown text file that tells AI shopping assistants — like the ones built into search engines, browsers, and voice assistants — what your store sells and how to describe it. Cassian doesn't score your store on whether one exists, but the AI Product Feeds feature (Analyst and above) generates a complete llms.txt from your catalogue, ready to download and deploy to your domain root.

Does Cassian check my robots.txt? Not currently — Disallow rules in robots.txt aren't parsed or validated. Cassian does check each page for a robots meta tag (<meta name="robots">), which appears under the LLM Readiness filter when missing.

I fixed a broken link but it's still showing in Issues. Broken-link results come from the most recent link check, which runs on its own schedule (weekly on Inspector and Analyst, daily on Protector and above). Once the next link check runs and confirms the fix, the issue clears from your results.