📖 Guide

HTML — Complete Reference

Comprehensive HTML cheat sheet covering document structure, text content, forms, media, semantic elements, accessibility, and more.

142 commands across 10 categories

Document StructureText ContentLinks & NavigationImages & MediaForms & InputTablesSemantic ElementsMeta & HeadAttributesAccessibility

Document Structure

CommandDescription
<!DOCTYPE html>
HTML5 document type declaration (must be first line)
<html lang="en">
Root element with language attribute
<head>
Contains metadata, links, scripts, and title
<body>
Contains all visible page content
<title>Page Title</title>
Set the page title (shown in browser tab)
<link rel="stylesheet" href="style.css">
Link an external stylesheet
<script src="app.js"></script>
Link an external JavaScript file
<script defer src="app.js"></script>
Load script after HTML parsing (recommended)
<script type="module" src="app.js"></script>
Load script as ES module (deferred by default)
<noscript>JS required</noscript>
Fallback content when JavaScript is disabled
<!-- comment -->
HTML comment (not rendered)

Text Content

CommandDescription
<h1> to <h6>
Heading levels (h1 = most important)
<p>
Paragraph
<br>
Line break
<hr>
Horizontal rule (thematic break)
<strong>
Strong importance (typically bold)
<em>
Emphasis (typically italic)
<b>
Bold text (no extra importance)
<i>
Italic text (alternative voice, technical terms)
<u>
Underlined text (annotated as misspelled)
<s>
Strikethrough (no longer relevant)
<mark>
Highlighted/marked text
<small>
Small print / side comments
<sub> / <sup>
e.g. H<sub>2</sub>O, x<sup>2</sup>
Subscript / Superscript
<code>
Inline code
<pre>
Preformatted text (preserves whitespace)
<blockquote cite="url">
Block quotation with optional source
<q>
Inline quotation (browser adds quotes)
<abbr title="full">
e.g. <abbr title="HyperText Markup Language">HTML</abbr>
Abbreviation with expansion
<cite>
Title of a creative work
<kbd>
e.g. Press <kbd>Ctrl</kbd>+<kbd>C</kbd>
Keyboard input

Images & Media

CommandDescription
<img src="img.jpg" alt="description">
Image with alt text (required for accessibility)
<img loading="lazy">
Lazy load image (loads when near viewport)
<img srcset="sm.jpg 480w, lg.jpg 1024w" sizes="(max-width: 600px) 480px, 1024px">
Responsive image with multiple sources
<picture>
e.g. <picture><source media="(min-width: 800px)" srcset="lg.jpg"><img src="sm.jpg" alt=""></picture>
Container for multiple image sources
<video src="vid.mp4" controls>
Video with playback controls
<video autoplay muted loop playsinline>
Autoplaying background video
<audio src="sound.mp3" controls>
Audio player with controls
<source src="vid.webm" type="video/webm">
Alternative media source
<figure> / <figcaption>
e.g. <figure><img src="chart.png" alt="Sales chart"><figcaption>Q1 Sales</figcaption></figure>
Figure with caption
<canvas id="c" width="400" height="300">
Drawing surface for JavaScript graphics
<svg viewBox="0 0 100 100">
Scalable Vector Graphics container
<iframe src="url" title="desc">
Embed external content (use title for a11y)

Forms & Input

CommandDescription
<form action="/submit" method="POST">
Form element with action and method
<input type="text" name="field">
Text input
<input type="email">
Email input (with validation)
<input type="password">
Password input (masked)
<input type="number" min="0" max="100" step="1">
Number input with constraints
<input type="range" min="0" max="100">
Slider input
<input type="date">
Date picker
<input type="checkbox">
Checkbox
<input type="radio" name="group">
Radio button (same name = same group)
<input type="file" accept=".pdf,.jpg" multiple>
File upload input
<input type="hidden" name="token" value="abc">
Hidden input (not visible)
<input type="search">
Search input (may show clear button)
<input type="color">
Color picker
<textarea rows="4" cols="50">
Multi-line text input
<select> / <option>
e.g. <select><option value="a">A</option></select>
Dropdown select menu
<label for="inputId">
Label associated with input (click focuses input)
<fieldset> / <legend>
Group related form controls with a caption
<button type="submit">Send</button>
Submit button
<input required>
Mark input as required
<input placeholder="Enter name">
Placeholder text
<input pattern="[A-Za-z]{3,}">
Regex validation pattern
<datalist id="opts">
e.g. <input list="opts"><datalist id="opts"><option value="One"></datalist>
Predefined options for input autocomplete
<output>
Result of a calculation or user action

Tables

CommandDescription
<table>
Table container
<thead>
Table header group
<tbody>
Table body group
<tfoot>
Table footer group
<tr>
Table row
<th scope="col">
Table header cell (use scope for accessibility)
<td>
Table data cell
<td colspan="2">
Cell spanning multiple columns
<td rowspan="3">
Cell spanning multiple rows
<caption>
Table caption (describes the table)
<colgroup> / <col>
Group columns for styling

Semantic Elements

CommandDescription
<header>
Introductory content or navigation container
<footer>
Footer for section or page
<main>
Main content of the document (only one per page)
<nav>
Navigation links section
<article>
Self-contained content (blog post, comment)
<section>
Thematic grouping of content
<aside>
Sidebar / tangentially related content
<details> / <summary>
e.g. <details><summary>More info</summary><p>Hidden content</p></details>
Collapsible disclosure widget
<dialog>
e.g. <dialog open>Content</dialog>
Modal or non-modal dialog box
<time datetime="2024-01-15">
Machine-readable date/time
<address>
Contact information for author/owner
<template>
Inert HTML template (not rendered until cloned via JS)

Meta & Head

CommandDescription
<meta charset="UTF-8">
Character encoding (always use UTF-8)
<meta name="viewport" content="width=device-width, initial-scale=1">
Responsive viewport meta tag
<meta name="description" content="...">
Page description for SEO
<meta name="robots" content="noindex, nofollow">
Control search engine indexing
<meta property="og:title" content="...">
Open Graph title for social sharing
<meta property="og:image" content="url">
Open Graph image for social sharing
<meta name="theme-color" content="#0066ff">
Browser theme color (mobile)
<link rel="icon" href="favicon.ico">
Favicon
<link rel="preconnect" href="https://fonts.googleapis.com">
Preconnect to required origin (performance)
<link rel="preload" href="font.woff2" as="font" crossorigin>
Preload critical resource
<link rel="canonical" href="https://example.com/page">
Canonical URL to avoid duplicate content
<base href="/app/">
Base URL for all relative URLs in the document

Attributes

CommandDescription
id="unique"
Unique identifier for the element
class="cls1 cls2"
CSS class(es) for styling
style="color: red"
Inline CSS styles
title="tooltip text"
Tooltip on hover
data-*="value"
e.g. <div data-user-id="42">
Custom data attributes
hidden
Hide element from rendering
contenteditable="true"
Make element editable by user
draggable="true"
Make element draggable
spellcheck="false"
Disable spell checking
tabindex="0"
Make element focusable via Tab key
tabindex="-1"
Focusable via JS only (removed from tab order)
lang="en"
Language of element content
dir="rtl"
Text direction (right-to-left)
translate="no"
Prevent translation of element content
autofocus
Automatically focus element on page load
inert
Make element and descendants non-interactive
popover
e.g. <div popover id="pop">Content</div><button popovertarget="pop">Toggle</button>
Popover element (toggleable, ES2024)

Accessibility

CommandDescription
alt="description"
Alternative text for images (required)
alt=""
Empty alt for decorative images (skip by screen readers)
role="button"
ARIA role — define element's purpose
role="navigation"
ARIA role for navigation landmark
aria-label="Close menu"
Accessible label when visible text is insufficient
aria-labelledby="heading-id"
Reference another element as label
aria-describedby="desc-id"
Reference element providing additional description
aria-hidden="true"
Hide element from assistive technology
aria-expanded="false"
Indicate expandable element state
aria-live="polite"
Announce dynamic content changes to screen readers
aria-required="true"
Indicate required form field
aria-current="page"
Indicate current item in navigation
<label for="id">
Associate label with form control (critical for a11y)
skip navigation link
e.g. <a href="#main" class="sr-only">Skip to content</a>
Allow keyboard users to skip to main content

More Guides

🌿
Git Commands
Complete Git command reference cheat sheet — from basics to advanced workflows, including branching, stashing, rebasing, and tagging. Searchable, with examples.
📝
Vim Commands
Complete Vim/Vi command reference cheat sheet — modes, motions, editing, search and replace, macros, registers, marks, and window management.
🐳
Docker Commands
Complete Docker & Docker Compose command reference cheat sheet — containers, images, volumes, networks, registry auth, buildx multi-platform builds, & cleanup.
🔤
Regex Reference
Complete regular expression reference cheat sheet — character classes, anchors, quantifiers, groups, lookaheads, flags, and JavaScript string methods.
🐧
Linux Commands
Complete Linux/Bash command reference cheat sheet — file management, text processing, networking, system admin, and shell scripting.
☸️
Kubernetes Commands
Complete Kubernetes & kubectl command reference cheat sheet — pods, deployments, services, secrets, namespaces, scaling, RBAC, networking, and Helm charts.
🐍
Python Reference
Complete Python reference — syntax, data structures, string methods, control flow, classes, error handling, file I/O, comprehensions, and built-ins.
🗃️
SQL Reference
Complete SQL reference cheat sheet — queries, joins, aggregation, subqueries, indexes, window functions, string and date functions, and database management.
🌐
Nginx Reference
Complete Nginx configuration reference — server blocks, locations, proxying, SSL, load balancing, caching, security headers, and rate limiting.
🔐
SSH Commands
Complete SSH reference — connections, key management, tunneling, config, SCP/SFTP, agent forwarding, security hardening, and troubleshooting.
👷
Jenkins Reference
Complete Jenkins reference — pipeline syntax, Jenkinsfile, plugins, CLI, agents, shared libraries, credentials, and CI/CD patterns.
📨
HTTP Headers Reference
Complete HTTP headers reference — request headers, response headers, caching, security, CORS, and content negotiation. Searchable, with examples.
🐘
PostgreSQL Reference
Comprehensive PostgreSQL reference — from connection basics to advanced features like JSONB, full-text search, window functions, and performance tuning.
⚡
Async Patterns Reference
Multi-language async/concurrency patterns — JavaScript, Python, Go, Rust, Java, plus retry, rate limiting, and circuit breaker patterns.
📡
Protobuf & gRPC Reference
Comprehensive reference for Protocol Buffers (proto3) and gRPC — message definitions, services, streaming, and common patterns.
📚
JS Array Methods
Complete JavaScript Array methods reference — creating, searching, transforming, sorting, iterating, and common patterns. Searchable, with examples.
🌊
Tailwind CSS Reference
Complete Tailwind CSS reference — layout, spacing, typography, colors, responsive design, states, and common patterns. Searchable, with examples.
◈
GraphQL Reference
Complete GraphQL reference — schema definition, types, queries, mutations, directives, fragments, and common patterns. Searchable, with examples.
💻
VS Code Shortcuts
Complete VS Code keyboard shortcuts cheat sheet — editing, navigation, search, multi-cursor, terminal, debug, and more. Searchable, with Cmd/Ctrl notation.
🔲
CSS Grid Reference
Complete CSS Grid reference — container properties, item placement, grid functions, and common layout patterns. Searchable, with examples.
📦
CSS Flexbox Reference
Complete CSS Flexbox reference — container properties, item properties, and common layout patterns. Searchable, with examples.
⚛️
React Hooks Reference
Complete React Hooks reference — useState, useEffect, useContext, custom hooks, and common patterns. Searchable, with examples.
🔷
TypeScript Reference
Complete TypeScript reference — types, interfaces, generics, utility types, and advanced patterns. Searchable, with examples.
☁️
AWS CLI Reference
Complete AWS CLI reference — EC2, S3, IAM, Lambda, ECS, RDS, CloudFormation, CloudWatch, SQS/SNS, Route 53, and common operations.
🐹
Go Reference
Complete Go (Golang) reference — syntax, types, structs, interfaces, goroutines, channels, error handling, testing, and the standard library.
💠
PowerShell Reference
Complete PowerShell reference — cmdlets, pipelines, scripting, file operations, remote management, and Active Directory.
💾
Redis Commands
Complete Redis command reference — strings, hashes, lists, sets, sorted sets, pub/sub, transactions, and server management.
🏗️
Terraform Commands
Complete Terraform reference — init, plan, apply, state management, modules, workspaces, providers, backend configuration, and HCL syntax.
⚙️
Ansible Commands
Complete Ansible reference — playbooks, modules, inventory, roles, vault, Galaxy, handlers, conditionals, loops, and ad-hoc commands.
🪶
Apache
Complete Apache HTTP Server cheat sheet — virtual hosts, modules, rewrite rules, and SSL, plus access control, logging, and performance.
🔤
ASCII Table
Complete ASCII character reference with decimal, hexadecimal, and character values, plus control codes and common escape sequences.
🔧
Awk
Powerful text processing language for pattern scanning, data extraction, arrays, control flow, and report generation with built-in variables.
💻
Bash
Complete Bash reference cheat sheet — variables, strings, arrays, conditionals, loops, functions, file tests, I/O redirection, process management, and more.
⚙️
C
Complete C programming cheat sheet covering syntax, pointers, memory management, structs, file I/O, preprocessor, and standard library.
🔐
Chmod
Linux file permission commands and patterns for chmod, covering numeric and symbolic modes, recursive changes, and SUID/SGID/sticky bits.
🔧
Chrome DevTools
Essential Chrome DevTools shortcuts, commands, and workflows for web developers — covering Network, Performance, and Application panels.
🔷
C++
Complete C++ cheat sheet covering STL containers, OOP, templates, smart pointers, iterators, lambda expressions, and modern C++ features.
⏰
Cron
Cron scheduling reference covering syntax, special strings, field values, crontab management, environment variables, and logging.
🎨
CSS
Complete CSS reference cheat sheet — selectors, box model, positioning, typography, animations, media queries, custom properties, and more.
🌐
Curl
Curl command-line reference for HTTP requests, headers, authentication, cookies, proxies, file transfers, SSL/TLS, debugging, and API patterns.
🎯
Dart
Dart language cheat sheet covering syntax, types, OOP, null safety, and async patterns, plus collections, error handling, and classes.
🐳
Docker Compose
Docker Compose reference covering CLI commands, service configuration, networking, volumes, health checks, profiles, and build options.
💧
Drizzle ORM
Complete Drizzle ORM reference for schema definition, column types, queries, filters, joins, relations, migrations, indexes, and patterns.
⚡
Emmet
Quick reference for Emmet abbreviations for lightning-fast HTML and CSS coding, covering nesting, multiplication, numbering, and grouping.
🔍
Find
Search for files and directories in a directory hierarchy with powerful filtering by name, size, time, permissions, type, and actions.
🔥
Firebase
Firebase reference covering Authentication, Firestore, Realtime Database, Cloud Functions, Hosting, Storage, and security rules.
🤖
GitHub Actions
Complete GitHub Actions cheat sheet — workflows, triggers, jobs, and CI/CD patterns, plus matrix strategies, caching, and artifacts.
🔎
Grep
Search text using patterns. Filter lines from files, command output, or streams with regular expressions, context options, and file filtering.
📡
HTTP Status Codes
Complete reference of all standard HTTP response status codes across 1xx-5xx classes, with descriptions, examples, and common usage patterns.
☕
Java
Complete Java reference — data types, strings, collections, OOP, interfaces, exceptions, file I/O, streams, lambdas, and more.
🟨
JavaScript
Complete JavaScript reference — variables, types, operators, strings, arrays, objects, functions, async, DOM, ES6+, and more.
💲
jQuery
Quick reference for jQuery selectors, DOM manipulation, events, AJAX, and more, including animation effects, traversing, and plugins.
🔺
Laravel
Laravel PHP framework cheat sheet for routing, Eloquent, Blade, Artisan, and more, plus middleware, validation, and authentication.
📐
LaTeX
Quick reference for LaTeX document structure, math mode, formatting, and common packages, plus figures, tables, and citation styles.
📝
Markdown
Complete Markdown syntax reference for headings, formatting, links, tables, code blocks, task lists, footnotes, and extensions.
🍃
MongoDB
MongoDB reference covering CRUD operations, aggregation, indexes, and administration, plus replica sets, users, roles, and query operators.
🐬
MySQL
Complete MySQL cheat sheet covering queries, joins, indexes, transactions, data types, user permissions, and database administration.
▲
Next.js
Next.js App Router reference covering routing, data fetching, server components, API routes, middleware, and deployment configuration.
🟩
Node.js
Comprehensive Node.js runtime reference covering modules, file system, HTTP, streams, events, child processes, and npm scripts.
📦
npm
Complete npm cheat sheet — package management, scripts, publishing, and configuration, plus workspaces, security audits, and npx.
🔢
NumPy
Essential NumPy commands for array manipulation and numerical computing in Python, covering reshaping, broadcasting, and linear algebra.
🐼
Pandas
Pandas cheat sheet for data manipulation, analysis, and transformation in Python, covering DataFrames, grouping, merging, and date/time.
🐘
PHP
Complete PHP cheat sheet covering syntax, OOP, arrays, PDO, and modern PHP 8.x features, plus file I/O, superglobals, and error handling.
🔄
PM2
Production process manager for Node.js applications with cluster mode, monitoring, log management, startup scripts, and zero-downtime reloads.
💎
Prisma
Complete Prisma ORM cheat sheet — schema, queries, migrations, and CLI, plus relations, aggregations, filtering, and seeding patterns.
🦀
Rust
Comprehensive Rust language cheat sheet covering ownership, traits, pattern matching, structs, enums, error handling, closures, and concurrency.
💅
Sass
Complete Sass/SCSS cheat sheet covering variables, mixins, functions, nesting, extends, maps, and the modern module system.
📺
Screen
GNU Screen terminal multiplexer for persistent sessions, window and split-region management, key bindings, copy mode, and remote work.
✂️
Sed
Stream editor for filtering and transforming text, line by line — substitution, address ranges, hold space, branching, and flags.
⚡
Supabase
Complete Supabase cheat sheet — auth, database, realtime, storage, and edge functions, plus row level security and migrations.
🖥️
Tmux
Terminal multiplexer cheat sheet for managing multiple sessions, windows, and panes from a single terminal, with copy mode and status bar configuration.
📦
TOML
Quick reference for TOML configuration file syntax, types, tables, and common patterns, including arrays of tables and inline tables.
▲
Vercel CLI
Complete Vercel CLI reference for deployment, project management, domains, environment variables, secrets, logs, edge functions, and configuration.
⚡
Vite
Next-generation frontend build tool with instant HMR, native ES modules, plugins, environment variables, library mode, and Rollup-based builds.
📦
Webpack
Module bundler for JavaScript applications — entry/output config, loaders, plugins, code splitting, module resolution, and optimization.
🎯
XPath
Quick reference for XPath expressions, axes, predicates, string functions, node tests, and operators for XML/HTML querying.
📋
YAML
YAML syntax reference covering scalars, collections, anchors, aliases, multi-line strings, nested structures, and common patterns.

📖 Free, searchable command reference. Bookmark this page for quick access.