Alt attributes provide a text alternative for images, used by screen readers when a user cannot see the image and by search engines and multimodal AI models to understand what the image depicts. Fixing this issue means writing concise, descriptive alt text for every meaningful image on the page, and using empty alt for purely decorative images so assistive technology can skip them. The same alt text helps multimodal LLMs and image search tools surface and cite your visuals.

Example

<img src="/images/marathon-shoes.jpg"
     alt="Side view of a lightweight neon-green marathon running shoe">

<img src="/images/divider.svg" alt="">

Where to make the change

• Raw HTML: add the alt attribute to every <img> tag. For decorative images, use alt="" so screen readers skip them.
• WordPress: the media library has an Alt text field on every uploaded image. Fill it once and the value is reused everywhere the image is inserted.
• Shopify: in the product or page editor, click an image and use the Edit alt text option. Theme code that renders product images should pull image.alt.
• Wix or Squarespace: click the image in the editor and use the Alt text or Image description field in the side panel.
• Headless or framework sites: require an alt prop on every image component and lint for missing values during build.

Common causes and how to resolve them

• Attribute missing: add alt="" at minimum so the page validates. Replace with descriptive text on any image that conveys information.
• Alt text is the filename: "IMG_4837.jpg" tells the user nothing. Replace with a description of what is in the image.
• Alt text duplicates the visible caption: screen readers will read both, doubling the user's listening time. Differentiate the alt from the caption or empty the alt.
• Decorative images get descriptive alt text: background patterns and dividers should use alt="", otherwise screen readers narrate noise.
• Bulk imports left alt blank: a one-off audit of the media library or a CMS-side script can fill missing alt values from product names, captions, or asset descriptions.

Best practices

• Describe the function, not just the appearance: for a chart, describe what the chart shows. For a button image, describe what the button does.
• Keep it concise: aim for under 125 characters. Screen readers do not pause mid-sentence, so long alt text is exhausting to listen to.
• Skip "image of" or "picture of": the screen reader already announces it as an image.
• Include the focus keyword when natural: alt text is a minor on-page signal, but stuffing keywords in unnatural alt text harms both accessibility and ranking.

Google Analytics 4 is a free measurement platform that records visitor behavior, traffic sources, and conversion data. Installing it does not directly affect rankings, but the data it produces is essential for measuring SEO performance, identifying high-value pages, and prioritizing future optimization work. Fixing this issue means installing the GA4 tag site-wide and confirming events appear in your reports.

Example

<!-- Place inside <head> on every page -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-XXXXXXXXXX"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'G-XXXXXXXXXX');
</script>

Where to make the change

• Raw HTML: paste the GA4 snippet into the <head> of every page. A shared layout file is the cleanest place.
• WordPress: use a site-kit or analytics plugin, or paste the snippet into your theme's header file. Avoid duplicating the tag across multiple plugins.
• Shopify: add the GA4 measurement ID under Online Store, Preferences, Google Analytics, or install the official Google channel app.
• Wix or Squarespace: both platforms offer a GA4 measurement ID field in their analytics settings panel.
• Headless or framework sites: install via Google Tag Manager or use the framework's analytics integration so the tag fires on every route change.

Common causes and how to resolve them

• Tag not installed at all: install GA4 using the snippet above or the platform-specific path.
• Universal Analytics tag still in place: Universal Analytics stopped processing data on July 1, 2024. Replace any UA tag (UA-...) with a GA4 measurement ID (G-...).
• Tag fires only on the homepage: ensure the snippet is in a shared template loaded by every page, not pasted into one post.
• Cookie banner blocks the tag before consent: integrate Consent Mode v2 so GA4 receives anonymized signals before consent and full data after.
• Tag duplicated: two snippets on the same page double-count sessions. Audit with the Tag Assistant browser extension and remove duplicates.

Best practices

• Verify with real-time reports: after installing, open GA4's Realtime view and load the site to confirm events arrive.
• Use Google Tag Manager: for any site beyond the simplest, GTM gives you a single place to manage analytics, conversion tags, and third-party scripts without code changes.
• Configure key events: mark conversions (purchase, lead, signup) as key events so reports highlight what matters for SEO ROI.
• Link to Search Console: connecting GA4 to Search Console surfaces organic queries alongside on-site behavior in the same reports.

This test fails when the page builds a Document Object Model with too many nodes or excessive nesting depth. Large DOMs increase memory usage, lengthen style and layout calculations, and slow rendering, particularly on mobile devices. Fixing this issue means simplifying the markup so the browser has less work to do on every interaction.

Where to make the change

• Application code or templates: identify the heaviest sections (long lists, repeating components, deep grid wrappers) and either paginate them, virtualize them, or flatten the markup.
• WordPress: heavy page-builder themes often emit deeply nested wrapper divs. Consider switching templates or using a theme that emits cleaner markup.
• Headless or framework sites: use a virtualized list component for long item lists so only visible rows are rendered into the DOM.

Common causes and how to resolve them

• Long lists rendered in full: show a paginated subset or virtualize the list so only on-screen items exist in the DOM.
• Excessive wrapper divs: a stack of layout wrappers ten deep can usually be flattened to two or three with modern CSS layouts (Grid, Flexbox).
• Hidden modals and dropdowns kept in the DOM: render them on demand instead of always emitting them with display: none.
• Third-party widget injecting many nodes: a chat widget or carousel may add hundreds of nodes per page. Lazy-load it after main content renders.

Best practices

• Aim for under 1500 nodes total and a maximum depth of 32: Lighthouse uses these as warning thresholds and they correlate with smooth rendering on mid-tier mobile devices.
• Render only what is visible: long lists, accordions, and modals belong outside the initial DOM until needed.
• Prefer flat semantic markup: a single <article> with a few children is faster than a deeply nested <div> tree.
• Audit with Lighthouse: the DOM size audit reports the worst-offending elements, which often points at a single template that needs rework.

This test fails when the page exposes one or more email addresses in plain text. Spam-harvesting bots scrape pages for plaintext addresses and add them to bulk mailing lists. Fixing this issue means obfuscating contact addresses, using a contact form, or rendering them via JavaScript so simple scrapers cannot read them.

Where to make the change

• Application code or templates: replace plain contact@example.com text with one of the obfuscation techniques below.
• WordPress: a contact form plugin handles email submissions without exposing the address. Some SEO and security plugins also offer email obfuscation.
• Shopify, Wix, Squarespace: use the platform's built-in contact form blocks rather than displaying the email address directly.

Common causes and how to resolve them

• Plain text address in a paragraph or footer: replace with a contact form, an obfuscated rendering (HTML entities, CSS reversal), or a JavaScript-built mailto link.
• Mailto link with the address visible: the visible text is what bots read. Make the visible text a label like "Email us" while the href still works.
• Address baked into images is fine for SEO but bad for accessibility: screen readers cannot read it. Pair an image with a contact form instead.

Best practices

• Prefer contact forms: they reduce spam and make analytics easier.
• Use HTML entity encoding: writing co... for the address defeats the simplest scrapers, though sophisticated ones decode it.
• Render via JavaScript: building the mailto link client-side blocks scrapers that only read static HTML.
• Consider a Cloudflare-style email obfuscation: some CDNs automatically rewrite plaintext emails to obfuscated equivalents.

This test fails when external links opened in a new tab (with target="_blank") lack the rel="noopener" or rel="noreferrer" attributes. Modern browsers (Chrome 88+, Firefox 79+, Safari 12.1+) apply noopener implicitly, so this is largely a defense for older browsers and a way to keep the destination page from running in the same browser process as the original tab. Fixing this issue means adding the attributes explicitly to every external target="_blank" link.

Example

<a href="https://example.com" target="_blank" rel="noopener noreferrer">
  External link
</a>

Where to make the change

• Application code or templates: search for target="_blank" and add rel="noopener noreferrer" to each match. A simple find-and-replace handles most cases.
• WordPress: the block editor adds rel="noopener" automatically on every external link opened in a new tab. Older content may need a one-time bulk update.
• Shopify, Wix, Squarespace: editor-generated links typically include the rel attributes. Manual HTML embeds need them added.
• Headless or framework sites: wrap external links in a component that always sets the correct rel attributes.

Common causes and how to resolve them

• Hand-written external links missing the attribute: add rel="noopener noreferrer" to each one.
• Old content from before the editor added it automatically: a one-time bulk update through the database or CMS export covers it.
• Markdown-rendered content: configure the renderer to add the attributes to every external link by default.

Best practices

• Use noopener noreferrer together: noopener handles the security concern, noreferrer additionally hides the referring URL. Both are safe defaults for most external links.
• Reserve target="_blank" for genuinely external links: internal links should open in the same tab so users can use the back button naturally.
• Add a lint rule: ESLint plugins for React and similar frameworks can enforce the rel attribute automatically.

This test fails when the page's stylesheets do not use CSS media queries to adapt the layout to different screen sizes. Media queries are the primary mechanism for responsive design, allowing typography, spacing, and component arrangement to adjust gracefully across devices. Because Google now indexes the web mobile-first, the responsive mobile layout is effectively the version search engines crawl, evaluate, and rank.

Example

/* Mobile-first base styles */
.card { padding: 16px; font-size: 16px; }

/* Tablet and up */
@media (min-width: 768px) {
  .card { padding: 24px; font-size: 18px; }
}

/* Desktop */
@media (min-width: 1024px) {
  .card { padding: 32px; font-size: 20px; }
}

Where to make the change

• Stylesheets: add @media blocks for the breakpoints your design needs. Start with mobile-first base styles and layer larger screens on top.
• WordPress: most modern themes are responsive. If yours is not, switch to a current theme or add custom CSS for breakpoints.
• Shopify, Wix, Squarespace: all platforms ship responsive themes by default; failures usually point at custom CSS that hard-codes desktop widths.
• Headless or framework sites: CSS frameworks like Tailwind, Bootstrap, and CSS Modules all include responsive utilities; ensure you are using them.

Common causes and how to resolve them

• No media queries at all: add a few breakpoints based on your design. Common choices are 480, 768, 1024, and 1280 pixels.
• Fixed pixel widths everywhere: replace with relative units (rem, %, vw) and let media queries handle major layout shifts.
• Desktop-first styles overriding mobile: reorder so mobile styles are the base and larger breakpoints add desktop refinements.
• Modern layout primitives missing: CSS Grid and Flexbox often eliminate the need for many media queries by responding naturally to available space.

Best practices

• Mobile-first: base styles target mobile; min-width media queries layer enhancements for larger screens.
• Use container queries where supported: they let components respond to their container's size rather than the viewport, which is often more useful.
• Test on real devices: emulator views miss real-world issues such as touch target size and font rendering. Test on actual phones too.

This test fails when the page is being excluded from search engine indexes via a noindex directive in the robots meta tag or X-Robots-Tag HTTP header. A noindex on the wrong page is one of the most common ways important content silently disappears from search results. Fixing this issue means removing the directive from any page that should rank.

Where to make the change

• Raw HTML: remove <meta name="robots" content="noindex"> from the <head> of pages you want indexed.
• Server configuration: remove or update X-Robots-Tag: noindex response headers for affected URL paths.
• WordPress: in the post or page editor, your SEO plugin has a "Search engine visibility" toggle. Make sure it is set to allow indexing. Also check Settings, Reading, "Discourage search engines" — this site-wide flag must be off.
• Shopify: certain templates and resource types (search results, cart) are noindexed by default and should stay that way. For other URLs, edit theme.liquid to remove the conditional noindex.
• Headless or framework sites: remove the meta tag from the page's metadata configuration or layout file.

Common causes and how to resolve them

• Site-wide noindex left over from staging: the most common cause. Disable the global setting after launch.
• Per-page noindex set in the CMS by mistake: review the page's SEO settings and toggle indexing back on.
• X-Robots-Tag header set by server config: check the server or CDN rules; remove the header for production URLs.
• Noindex on category or tag pages that should rank: some SEO plugins noindex archives by default. Override the setting for archives that earn organic traffic.

Best practices

• Verify with URL Inspection in Search Console: the live test confirms whether Google currently sees the page as indexable.
• Audit after migrations: staging sites are usually noindexed; verify the directive is removed before traffic resumes.
• Keep noindex for thin or duplicate pages: not every page should rank. Internal search results, paginated archives, and login pages benefit from noindex.

This test reports on whether the page applies a nofollow directive that tells search engines not to follow outbound links. The nofollow attribute (and the related sponsored and ugc values) controls how link equity flows from your page. Fixing this issue means using the right rel value on each external link based on its purpose so signals are passed only where you intend.

Where to make the change

• Raw HTML: add rel="nofollow", rel="sponsored", or rel="ugc" to specific outbound links rather than blanket-applying them site-wide.
• WordPress: the block editor offers a "mark as nofollow" option per link, and SEO plugins can auto-tag external links by domain.
• Shopify, Wix, Squarespace: editor-generated links allow rel attribute toggles; manual HTML embeds need them set explicitly.
• Headless or framework sites: wrap external links in a component that decides the rel based on the link's classification.

Common causes and how to resolve them

• Site-wide nofollow on every external link: overly aggressive. Reserve nofollow for sponsored, untrusted, or user-generated content.
• Sponsored content not labeled: use rel="sponsored" on paid placements and affiliate links to comply with Google's link spam policy.
• User-generated content unmarked: comments, forum posts, and review user submissions should use rel="ugc".
• Trusted editorial links nofollowed: these should pass equity. Remove the nofollow.

Best practices

• Use the most specific value: sponsored for paid links, ugc for user content, nofollow for everything else you want to disclaim. They can be combined: rel="sponsored noopener".
• Do not nofollow internal links: "PageRank sculpting" with internal nofollow no longer works and just wastes crawl signal.
• Audit periodically: as content ages, sponsored relationships change. Review affiliate and partner links once a year.