Run any Skill in Manus with one click

html-standards

Stars5

Forks1

UpdatedJanuary 29, 2026 at 08:47

Guidelines for writing HTML that is accessible, semantic, maintainable, and secure. Use when working with .html, .vue, .twig, .php, .cshtml, .svelte files, or when the user asks about HTML structure, semantic markup, accessibility, or web security best practices.

Installation

Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.

Run Skill in Manus

Source

devbyray

devbyray/github-copilot-starter

View GitHub Repository View Creator Repositories

Download

Run Skill in Manus

Related occupationsSOC

Based on SOC occupation classification

Web DevelopersComputer and Mathematical Occupations·SOC 15-1254

SKILL.md

readonly

More from this repository

same repository

commit-conventions

devbyray/github-copilot-starter

Standards for writing clear and consistent commit messages using Conventional Commits format. Use when making git commits, reviewing commit history, creating pull requests, or when the user asks about commit message formatting, git workflows, or version control best practices.

2026-01-295

csharp-standards

devbyray/github-copilot-starter

C# coding standards and conventions including naming, formatting, and best practices. Use when working with .cs files, writing C# code, or when the user asks about C# naming conventions, code structure, XML documentation, or .NET development patterns.

2026-01-295

css-standards

devbyray/github-copilot-starter

Guidelines for writing CSS that is simple, readable, and maintainable. Use when working with .css, .scss, .sass files, CSS-in-JS, styled-components, or when the user asks about CSS organization, selectors, specificity, reusability, performance, or responsive design patterns.

2026-01-295

dotnet-development

devbyray/github-copilot-starter

.NET coding standards and conventions including project structure, dependency injection, and best practices. Use when working with .NET projects, ASP.NET Core, or when the user asks about .NET architecture, dependency injection, async patterns, or project organization.

2026-01-295

javascript-typescript-standards

devbyray/github-copilot-starter

Guidelines for writing JavaScript and TypeScript code that is simple, readable, and maintainable. Use when working with .js, .jsx, .ts, .tsx, .mjs, .cjs files, or when the user asks about JavaScript/TypeScript coding standards, ES2022 features, Node.js modules, async/await patterns, or testing with Vitest.

2026-01-295

markdown-standards

devbyray/github-copilot-starter

Documentation and content creation standards for Markdown files. Use when creating or editing .md files, writing documentation, README files, or when the user asks about Markdown formatting, content structure, front matter, or documentation best practices.

2026-01-295

name	html-standards
description	Guidelines for writing HTML that is accessible, semantic, maintainable, and secure. Use when working with .html, .vue, .twig, .php, .cshtml, .svelte files, or when the user asks about HTML structure, semantic markup, accessibility, or web security best practices.
metadata	{"author":"devbyray","version":"1.0","languages":"html, html5"}

HTML Standards & Best Practices

Apply these standards when writing HTML markup to ensure accessibility, semantics, maintainability, and security.

Structure & Semantics

1. Use Semantic HTML Elements

Prefer semantic elements over generic divs and spans:

Good:

<header>
	<nav>
		<ul>
			<li><a href="/">Home</a></li>
		</ul>
	</nav>
</header>

<main>
	<article>
		<h2>Article Title</h2>
		<section>
			<p>Content...</p>
		</section>
	</article>

	<aside>
		<h3>Related Links</h3>
	</aside>
</main>

<footer>
	<p>&copy; 2026 Company Name</p>
</footer>

Bad:

<div class="header">
	<div class="nav">...</div>
</div>

<div class="main">
	<div class="article">...</div>
</div>

2. Document Structure

Always use proper HTML5 document structure:

<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="UTF-8" />
		<meta name="viewport" content="width=device-width, initial-scale=1.0" />
		<title>Page Title</title>
	</head>
	<body>
		<!-- Content -->
	</body>
</html>

3. Heading Hierarchy

Use headings in logical order (H2, H3, H4, etc.)
Do NOT use <h1> (reserved for page title generation)
Don't skip heading levels

Good:

<h2>Main Section</h2>
<h3>Subsection</h3>
<h4>Detail</h4>

Bad:

<h1>Title</h1>
<!-- Don't use H1 -->
<h4>Content</h4>
<!-- Skipped H2, H3 -->

4. Code Organization

Indent nested elements consistently (2 spaces)
Use blank lines to separate logical sections
Keep lines readable (max 120 characters)

Accessibility

5. Images

All images must have descriptive alt text:

<!-- Informative image -->
<img src="chart.png" alt="Sales chart showing 20% increase in Q4 2025" />

<!-- Decorative image -->
<img src="divider.png" alt="" />

6. Forms

Always label form controls:

<form>
	<label for="email">Email address</label>
	<input type="email" id="email" name="email" required />

	<label for="password">Password</label>
	<input type="password" id="password" name="password" required />

	<button type="submit">Submit</button>
</form>

7. Keyboard Navigation

Ensure interactive elements are keyboard accessible:

<button type="button">Clickable Button</button>
<a href="/page">Link to Page</a>

<!-- Only use tabindex="0" for custom interactive elements -->
<div role="button" tabindex="0" onclick="handleClick()">Custom Button</div>

8. ARIA Attributes

Use ARIA only when native HTML is insufficient:

<!-- Good: Native HTML -->
<button>Click me</button>

<!-- OK: ARIA when needed -->
<button aria-label="Close dialog">×</button>

<!-- Good: ARIA for custom widgets -->
<div role="dialog" aria-labelledby="dialog-title" aria-modal="true">
	<h2 id="dialog-title">Dialog Title</h2>
</div>

Maintainability

9. Avoid Inline Styles and Scripts

Keep HTML clean by using external files:

Bad:

<div style="color: red; font-size: 20px;" onclick="alert('clicked')">Content</div>

Good:

<div class="error-text" data-action="show-alert">Content</div>

10. Consistent Naming

Use lowercase, hyphen-separated names:

<div class="main-header"></div>
<nav class="site-navigation"></nav>
<button id="submit-button">Submit</button>

11. Code Comments

Use comments to organize sections:

<!-- Header Section -->
<header>
	<!-- Navigation -->
	<nav>...</nav>
</header>

<!-- Main Content -->
<main>...</main>

Security

12. Escape User-Generated Content

Never inject raw user data into the DOM:

Bad (XSS vulnerability):

element.innerHTML = userInput

Good:

element.textContent = userInput
// OR use DOMPurify for HTML
element.innerHTML = DOMPurify.sanitize(userInput)

13. Security Meta Tags

Include security headers:

<head>
	<meta charset="UTF-8" />
	<meta http-equiv="Content-Security-Policy" content="default-src 'self'; script-src 'self' 'unsafe-inline'" />
	<meta http-equiv="X-Content-Type-Options" content="nosniff" />
	<meta http-equiv="Strict-Transport-Security" content="max-age=31536000; includeSubDomains" />
</head>

Performance

14. Optimize Images

<!-- Modern formats with fallback -->
<picture>
	<source srcset="image.webp" type="image/webp" />
	<source srcset="image.jpg" type="image/jpeg" />
	<img src="image.jpg" alt="Description" loading="lazy" />
</picture>

<!-- Lazy loading for non-critical images -->
<img src="image.jpg" alt="Description" loading="lazy" />

15. Resource Hints

Use preload and prefetch for critical resources:

<head>
	<!-- Preload critical CSS -->
	<link rel="preload" href="critical.css" as="style" />

	<!-- Prefetch next page -->
	<link rel="prefetch" href="/next-page" />

	<!-- DNS prefetch for external domains -->
	<link rel="dns-prefetch" href="https://api.example.com" />
</head>

Complete Example

<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="UTF-8" />
		<meta name="viewport" content="width=device-width, initial-scale=1.0" />
		<meta name="description" content="Brief page description for SEO" />
		<meta http-equiv="Content-Security-Policy" content="default-src 'self'" />

		<title>Page Title - Site Name</title>

		<link rel="preload" href="styles.css" as="style" />
		<link rel="stylesheet" href="styles.css" />
	</head>
	<body>
		<!-- Header -->
		<header class="site-header">
			<nav class="main-navigation" aria-label="Main navigation">
				<ul>
					<li><a href="/" aria-current="page">Home</a></li>
					<li><a href="/about">About</a></li>
					<li><a href="/contact">Contact</a></li>
				</ul>
			</nav>
		</header>

		<!-- Main Content -->
		<main id="main-content">
			<article>
				<h2>Article Title</h2>

				<section>
					<h3>Section Heading</h3>
					<p>Content paragraph with <a href="/link">descriptive link text</a>.</p>

					<img src="image.jpg" alt="Detailed description of the image" loading="lazy" />
				</section>

				<section>
					<h3>Form Section</h3>
					<form action="/submit" method="post">
						<label for="name">Full Name</label>
						<input type="text" id="name" name="name" required />

						<label for="email">Email Address</label>
						<input type="email" id="email" name="email" required />

						<button type="submit">Send</button>
					</form>
				</section>
			</article>

			<aside class="sidebar">
				<h3>Related Content</h3>
				<ul>
					<li><a href="/related-1">Related Article 1</a></li>
					<li><a href="/related-2">Related Article 2</a></li>
				</ul>
			</aside>
		</main>

		<!-- Footer -->
		<footer class="site-footer">
			<p>&copy; 2026 Company Name. All rights reserved.</p>
		</footer>

		<script src="app.js" defer></script>
	</body>
</html>

Validation

Tools

W3C Markup Validator
Browser DevTools accessibility audits
axe DevTools

Checklist

✅ Valid HTML5 structure
✅ Proper DOCTYPE and language attribute
✅ Semantic elements used appropriately
✅ No H1 in content (reserved for page title)
✅ All images have alt text
✅ Forms have proper labels
✅ Keyboard navigation works
✅ Security meta tags included
✅ External CSS/JS files used
✅ Consistent naming conventions

When to Apply

Apply these standards when:

Creating HTML pages
Building templates
Writing component markup
Reviewing HTML code
User asks about HTML best practices
Working with any HTML-based template engine