What does an HTML formatter do?
An HTML formatter takes minified or poorly indented HTML and restructures it with consistent indentation — typically 2 spaces per nesting level. The output is functionally identical to the input but is much easier to read, review, and edit. This is also known as HTML beautification.
When to format HTML
Minified HTML from build tools, templating engines, or email clients is nearly impossible to debug by eye. Formatting is the first step before inspecting a page structure, reviewing a template, or checking for missing closing tags. It is also useful when committing HTML to version control — formatted code produces cleaner diffs.
Block vs inline elements
This formatter treats block-level elements like div, section, article, and nav as nesting containers and indents their children. Inline elements like span, a, strong, and em are kept on the same line as their surrounding content. Void elements like img, br, and input are never given a closing indent level.
Limitations
This is a lightweight client-side formatter suitable for typical HTML snippets and full pages. It works best on well-structured HTML. For heavily nested or template-language HTML (e.g. Jinja, Handlebars), results may vary. For production-grade formatting, consider using Prettier in your development environment.