A skill your agent uses when auditing metadata, crawlability, structured data, or indexability related to Fix malformed HTML structure.

MITAuto-check passedMarketing & SEO

Install Broken HTML

skills CLI
$ npx skills add thedaviddias/Front-End-Checklist --skill broken-html -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install thedaviddias/Front-End-Checklist broken-html --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/broken-html .claude/skills/broken-html && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
broken-html
GitHub stars
74k
Token cost
~423 tokens
SKILL.md length
171 words
Files
2 (incl. references)
Skills in repo
390
Repo updated
First seen
Licence
MIT

At a glance

A skill your agent uses when auditing metadata, crawlability, structured data, or indexability related to Fix malformed HTML structure.

  • Auditing metadata
  • SKILL.md covers Quick Reference, Check, Fix and Explain, plus 1 more section
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
  • Structured data

What it does

Broken HTML is an agent skill from thedaviddias/Front-End-Checklist. Use when auditing metadata, crawlability, structured data, or indexability related to Fix malformed HTML structure. Verify the rendered HTML and HTTP response rather than relying only on source files.

Its SKILL.md is about 420 tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including reference files (for example `references/rule.md`).

It sits in Marketing & SEO, covering Technical SEO and Schema markup. The repository describes itself as: 🗂 The essential checklist for modern web development, for humans and AI agents. The licence is MIT.

When your agent uses it

  • Auditing metadata
  • Structured data
  • Indexability related to Fix malformed HTML structure

Example prompts

  • “/broken-html”

What it can do on your machine

Read from SKILL.md and the folder at commit e8d14d0. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md.

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Links to these hosts (documentation or services it may open):

    • frontendchecklist.io

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Broken HTML loads about 423 tokens when it runs, and up to ~1k if it reads all its reference files. Until then it costs about 53 tokens; SKILL.md has 171 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~53
When it runs · the whole SKILL.md, loaded when a task matches
~423
With references · SKILL.md plus every file in references/, read only if the agent opens them
~1k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from thedaviddias/Front-End-Checklist at commit e8d14d0, republished under its MIT licence (© thedaviddias). 171 words, ~423 tokens.

Download SKILL.mdSave it as .claude/skills/broken-html/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.
name
broken-html
description
Use when auditing metadata, crawlability, structured data, or indexability related to Fix malformed HTML structure. Verify the rendered HTML and HTTP response rather than relying only on source files.
metadata.category
seo
metadata.priority
medium
metadata.difficulty
intermediate
metadata.estimatedTime
10
metadata.source
frontendchecklist.io
metadata.url
https://frontendchecklist.io/rules/seo/broken-html

Fix malformed HTML structure

Malformed HTML can cause rendering issues across browsers and may prevent search engine crawlers from accurately parsing and indexing your content.

Quick Reference

  • Ensure all HTML tags are properly closed and nested according to specifications
  • Remove stray tags or unescaped characters from the source code
  • Verify the document structure follows a logical hierarchy with valid head and body sections

Check

Validate the HTML structure of the page to identify any unclosed tags, incorrect nesting, or structural errors.

Fix

Correct the malformed HTML by properly closing tags and ensuring all elements are nested according to the HTML5 specification.

Explain

Explain how significant HTML errors can impact search engine bot crawling and the accessibility of a website.

Code Review

Review metadata generation, rendered HTML, structured data, and response headers related to Fix malformed HTML structure. Flag exact routes or templates where search-facing output violates the rule, and describe how to verify the final page output.


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

Rule page: https://frontendchecklist.io/rules/seo/broken-html

© thedaviddias, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file (references) in skills/broken-html of thedaviddias/Front-End-Checklist.

  • SKILL.md
  • references/rule.md

Open the folder on GitHubat commit e8d14d0

Compare with similar skills

Broken HTML next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Broken HTML compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Broken HTML this skillthedaviddias/Front-End-Checklist74k—~423Automated safety check: PassMIT
GEO-First SEO Audit Toolzubair-trabzada/geo-seo-claude11k—~2.8kAutomated safety check: NotesMIT
SEO Optimizerailabs-393/ai-labs-claude-skills4541 repos~3.2kAutomated safety check: PassMIT
SEO and GEO Auditdageno-agents/seo-geo-audit176—~2kAutomated safety check: PassMIT
SEO Setupalisamadiii/Portfolio180—~1.7kAutomated safety check: PassNone
SEOever-works/ever-works16210 repos~2.9kAutomated safety check: PassMIT

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Categories

Questions about Broken HTML

What does Broken HTML do?

A skill your agent uses when auditing metadata, crawlability, structured data, or indexability related to Fix malformed HTML structure. Broken HTML is an agent skill from thedaviddias/Front-End-Checklist. Use when auditing metadata, crawlability, structured data, or indexability related to Fix malformed HTML structure.

When should I use Broken HTML?

Broken HTML fits situations like: auditing metadata; structured data; indexability related to Fix malformed HTML structure.

How do I install Broken HTML in Claude Code?

Run `npx skills add thedaviddias/Front-End-Checklist --skill broken-html -a claude-code`. Or copy the skill folder (skills/broken-html in thedaviddias/Front-End-Checklist) into .claude/skills/broken-html in your project. Claude Code loads it when a task matches its description.

How do I install Broken HTML in Codex?

Run `npx skills add thedaviddias/Front-End-Checklist --skill broken-html -a codex`. Or copy the skill folder (skills/broken-html in thedaviddias/Front-End-Checklist) into .agents/skills/broken-html in your project. Codex loads it when a task matches its description.

Can I use Broken HTML in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add thedaviddias/Front-End-Checklist --skill broken-html -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/broken-html, .gemini/skills/broken-html, .github/skills/broken-html and .opencode/skills/broken-html in your project.

What does Broken HTML need to run?

SKILL.md names no scripts, command-line tools or credentials: Broken HTML is instructions for the agent only.

Does Broken HTML access the network?

SKILL.md names 1 domain. As links in the text: frontendchecklist.io. This is read from the text; nothing was executed.

Is Broken HTML safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Broken HTML use?

Broken HTML is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Broken HTML use?

About 423 tokens (SKILL.md is roughly 1.7k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 599 tokens, read only when the agent opens those files.

What are the alternatives to Broken HTML?

Skills that share tags, products or a category with Broken HTML: GEO-First SEO Audit Tool (zubair-trabzada/geo-seo-claude, 11k stars), SEO Optimizer (ailabs-393/ai-labs-claude-skills, 454 stars), SEO and GEO Audit (dageno-agents/seo-geo-audit, 176 stars) and SEO Setup (alisamadiii/Portfolio, 180 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Broken HTML?

thedaviddias (a GitHub user) maintains it in thedaviddias/Front-End-Checklist, which has 74,412 GitHub stars. The repository holds 390 skills in this directory. The repository was last updated on October 6, 2026.

Source: thedaviddias/Front-End-Checklist on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.