The foundational markup language of the World Wide Web
HTML (HyperText Markup Language) is the standard markup language used to create web pages and web applications. It provides the structure for web content, enabling browsers to interpret and display text, images, multimedia, forms, and other content on the internet.
Developed by Tim Berners-Lee in 1991, HTML has evolved through multiple versions, with HTML5 being the current standard. The language uses a system of tags and attributes to define elements within a document, creating a structured representation of content that browsers can render.
While HTML itself focuses on content structure and semantics, it works alongside CSS (Cascading Style Sheets) for presentation and styling, and JavaScript for behavior and interactivity. Together, these three technologies form the cornerstone of modern web development, with HTML providing the foundation upon which the others build.
HTML documents consist of elements represented by tags, which are enclosed in angle brackets. Most elements have opening and closing tags, with content placed between them. The document structure typically includes a DOCTYPE declaration, html, head, and body elements. The head contains metadata, while the body contains the visible content. HTML5 introduced many new semantic elements (like <article>, <section>, <nav>) that better describe the purpose of content, as well as enhanced support for multimedia, forms, and application development.
HTML's primary purpose is creating websites and web pages. From simple personal sites to complex business portals, HTML provides the structure for all content on the web, enabling users to navigate, read, view, and interact with information online.
Modern HTML5, combined with CSS and JavaScript, supports sophisticated web applications like email clients, document editors, mapping services, and social media platforms. These applications deliver desktop-like functionality within a browser, accessible from any device with internet access.
HTML is extensively used for online documentation, manuals, knowledge bases, and tutorials. Its hypertext capabilities allow for easy navigation between topics, while semantic elements provide clear structure and accessibility for complex information.
HTML emails enable rich formatting, images, and links in email communications. While HTML email requires careful consideration for compatibility across email clients, it offers significantly enhanced presentation compared to plain text.
With features like local storage, service workers, and the application cache, HTML5 enables offline-capable web applications that continue functioning without an internet connection, synchronizing data when connectivity is restored.
HTML is supported by all web browsers, though support for specific features varies:
HTML is supported by a vast ecosystem of tools:
While primarily designed for browsers, HTML can be viewed in:
| Feature | HTML | Markdown | XML | EPUB | |
|---|---|---|---|---|---|
| Primary Purpose | Web pages | Print/display documents | Simplified content creation | Data interchange | E-books |
| Ease of Creation | |||||
| Layout Control | |||||
| Interactivity | |||||
| Platform Independence | |||||
| Multimedia Support |
HTML excels in creating interactive, multimedia-rich content for the web, with strong browser support and platform independence. PDF offers superior layout consistency for print-focused documents. Markdown provides the simplest authoring experience but with limited formatting control. XML is highly structured but focused on data rather than presentation. EPUB (which actually uses HTML internally) offers a specialized format for e-books with good device support.
When converting from document formats to HTML, be prepared for layout changes. Word processors like MS Word and document formats like PDF use fixed positioning that doesn't translate perfectly to HTML's flow-based layout. Use specialized conversion tools that preserve structure using appropriate HTML elements, and be prepared to manually adjust CSS for layout issues. Consider simplifying complex formatting before conversion.
Markdown to HTML conversion is generally straightforward as Markdown was designed with HTML generation in mind. Most Markdown processors offer options to control the generated HTML, including adding classes or IDs to elements. For consistent results, choose a specific Markdown flavor (CommonMark, GitHub Flavored Markdown, etc.) and corresponding parser.
When converting data to HTML, first decide on the appropriate presentation structure (tables, lists, cards, etc.). For tabular data like CSV, the <table> element with proper <thead> and <tbody> sections provides semantic structure. For hierarchical data like JSON, consider using nested lists, definition lists, or custom components with appropriate ARIA attributes for accessibility.
HTML to PDF conversion works best with specialized libraries or tools that properly handle CSS styling and pagination. For best results, create a print-specific CSS stylesheet that addresses page breaks, headers/footers, and adjusts styling for print. Test the generated PDFs across different browsers if using browser-based conversion, as rendering can vary significantly.
When converting HTML to Markdown, focus on content structure rather than visual appearance. Most converters handle basic elements well but may struggle with complex layouts or custom styling. Pre-process your HTML to simplify structure when possible, and be prepared to clean up the resulting Markdown for optimal readability.
HTML to plain text conversion necessarily loses formatting and structure. Focus on preserving content hierarchy through spacing and possibly ASCII-based formatting (like using asterisks for bullet points). Consider whether link URLs should be preserved in parentheses after the link text. For accessibility, ensure that alternative text for images is included in the plain text output.