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Broken HTML Checker

Audits pages for malformed HTML and suggests fixes that help browsers and search crawlers read them

Source Download skill
Repository
thedaviddias/Front-End-Checklist
Stars
74,632
Licence
MIT
Files
2 files

What it does

This skill gives an AI agent a checklist for finding HTML errors such as unclosed tags, bad nesting, stray characters and missing head or body structure. When asked, the agent reviews your templates or rendered pages against these rules, explains why the problems can affect search engine crawling and accessibility, and proposes corrections. It also tells the agent to check the final rendered HTML and HTTP response, not just source files.

Great for

  • Developers who want a second pair of eyes on SEO-facing templates before release
  • SEO or marketing staff investigating why a page may not be indexed or parsed correctly
  • Teams auditing a site for basic HTML validity

Skip it if

  • Replacing a full HTML validator or crawler: the skill is a guided checklist, so it may miss issues a dedicated tool would catch
  • Security or accessibility compliance sign-off, since it only covers structural HTML errors
  • Sites where the agent cannot see the rendered output: without the page or a fetch, it can only reason about source files

Try asking

  • “Audit the templates in this project for unclosed or misnested tags that could hurt SEO”
  • “Check the rendered HTML of https://example.com/pricing and tell me what is malformed”
  • “Review our product page template and explain how the broken markup could affect crawling”
Step-by-step guide: how to use Broken HTML CheckerInstall, first run, examples, tips and FAQs

Install in 3 steps

  1. 1

    Download the skill

    The ZIP contains the 2 original files, the MIT licence and an attribution note.

    broken-html.zip
  2. 2

    Add it to your agent

    Claude Code (all projects)

    mkdir -p ~/.claude/skills && unzip broken-html.zip -d ~/.claude/skills/

    Claude Code / Agent SDK (this project only)

    mkdir -p .claude/skills && unzip broken-html.zip -d .claude/skills/

    Claude apps (web/desktop): Settings → Capabilities → Skills → Upload skill, and choose the ZIP.

  3. 3

    Ask for the task

    No special command needed — the agent reads the skill's description and loads it when your request matches. Try one of the prompts above.

Get better results

  • Give the agent the rendered HTML or a URL to fetch, since the skill asks it to verify final output rather than source alone
  • Name specific routes or templates so the agent can flag exact places where output violates the rule
  • Ask for a prioritised list of fixes with the reason each one matters for crawling

What's inside

  • references/rule.md
  • SKILL.md

Redistributed unmodified from thedaviddias/Front-End-Checklist under the MIT licence. The assessment was drafted with AI from the skill's files on 2026-10-29. Skills can instruct your agent to run code — read SKILL.md and any scripts before installing.