Convert HTML to XHTML

Understanding HTML and XHTML file formats

HTML (HyperText Markup Language) is the standard markup language used to create web pages. It is flexible and forgiving, allowing for minor syntax errors without breaking the page rendering. XHTML (Extensible HyperText Markup Language) is a stricter, XML-based version of HTML. XHTML requires well-formed markup, proper nesting, and all tags to be closed, making it more suitable for data interchange and strict web standards compliance.

Why convert HTML to XHTML?

Converting HTML to XHTML ensures your web documents are well-formed and compatible with XML parsers. This is important for web applications that require strict syntax, improved interoperability, and future-proofing for evolving web standards.

How to convert HTML to XHTML

To convert an HTML file to XHTML, you need to:

• Ensure all tags are properly closed (e.g., <br /> instead of <br>).
• Use lowercase for all tag and attribute names.
• Quote all attribute values.
• Include the correct DOCTYPE declaration for XHTML.

Best software and converters for HTML to XHTML

Tidy is a widely recommended tool for converting HTML to XHTML. It automatically corrects markup errors and outputs well-formed XHTML. Tidy is available as a command-line tool and as plugins for various editors.

To convert using Tidy:

1. Install Tidy from https://www.html-tidy.org/.
2. Run the following command in your terminal:
   tidy -asxhtml -o output.xhtml input.html

Alternatively, online converters like FreeFormatter HTML to XHTML Converter can be used for quick conversions without installation.

Manual conversion using editors

Many code editors, such as Visual Studio Code or Notepad++, can assist in manual conversion. Use their search and replace features to close tags and correct syntax. For exporting, use File → Save As and select the .xhtml extension.

Summary

Converting HTML to XHTML ensures strict compliance with web standards and XML compatibility. Tidy is the best tool for automated conversion, while online converters and code editors offer alternative solutions for different needs.