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invalid-links

Testing & Quality
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Use when auditing a page's link elements for crawlability, reviewing JavaScript-heavy SPAs where navigation may not use `<a href>` tags, or checking that dynamically generated links have valid href values.

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Source SKILL.md: https://github.com/thedaviddias/Front-End-Checklist/blob/HEAD/skills/invalid-links/SKILL.md

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Fix invalid links

Google can only follow links declared as valid <a href> elements with crawlable URL values. Invalid links — empty hrefs, JavaScript voids, or non-URL content — prevent PageRank from flowing to linked pages and stop Googlebot from discovering those destinations.

Quick Reference

  • Invalid <a> tags (empty href, JavaScript voids, non-URL values) are not crawlable — Googlebot cannot follow them
  • Links must use crawlable <a href='...'> elements with valid absolute or relative URLs to pass PageRank and be followed
  • JavaScript-only navigation (onClick handlers without href) is invisible to search engine crawlers

Check

Parse all <a> elements on the page. Flag links where href: (1) is empty (href='' or href='#' with no meaningful target). (2) starts with javascript: (e.g., href='javascript:void(0)'). (3) starts with mailto: or tel: — these are valid but not crawlable for page discovery. (4) contains only a fragment identifier that references an anchor not present on the page. (5) is absent entirely (<a> without any href attribute). Report the count per type.

Fix

  1. For links using href='javascript:void(0)' or href='#' as navigation triggers:
    • Add a real URL as the href value
    • Use JavaScript to enhance the navigation, not replace it
    • Before: <a href="javascript:void(0)" onclick="openModal()">View Details</a>
    • After: <a href="/products/details" onclick="openModal(event)">View Details</a>
  2. For <a> elements without href (used as button-like elements):
    • If they trigger navigation: add href
    • If they trigger actions only: change to <button> elements
  3. For empty href='': either add the correct URL or remove the <a> wrapper
  4. For href='#' anchors: use meaningful fragment IDs that reference actual page sections (href='#features' where id='features' exists)

Explain

Google's documentation states that crawlable links must be <a> tags with an href attribute containing a valid URL. Links with javascript: hrefs, empty hrefs, or no href attribute are not followed by crawlers. This means pages only reachable through invalid links are not discovered by Googlebot, and any intended PageRank flow is blocked.

Code Review

Query all <a> elements in the rendered DOM. For each, extract the href attribute. Flag: absent href, empty string, '#' only, values starting with javascript:, values starting with void. Separately flag <div>, <span>, or <button> elements with onclick navigation handlers that lack a corresponding <a href> — these are not crawlable.

For full implementation details, code examples, and framework-specific guidance, see references/rule.md.

Rule page: https://frontendchecklist.io/en/rules/seo/invalid-links