HTML Formatter

An HTML formatter indents nested tags for readability (format) or strips unnecessary whitespace to shrink payload size (minify). The hard part is that whitespace in HTML is not always meaningless: the newlines and indentation between block-level tags rarely affect rendering, but the whitespace inside `<pre>` and `<textarea>` is displayed or used as the initial value verbatim, and a single space next to an inline element in `<p>text <a>link</a></p>` renders as a real gap between words. A tool that blindly re-indents everything without telling these apart can silently change how a page looks or what a form field starts with. toco.tools's HTML formatter deliberately avoids `DOMParser`, because it normalises the document — inserting html/head/body, relocating misplaced nodes — so the output would no longer be the document you wrote. Instead it tokenizes the source with a character-scanning parser that correctly handles `>` inside quoted attribute values and never mistakes a `<` inside a `<script>`/`<style>` string for a tag, then builds an element tree before rendering. `<pre>` and `<textarea>` contents are never touched, not even a single byte, in either format or minify mode. `<script>`/`<style>` contents are never re-parsed as HTML (format shifts the whole block to the new indent level as a unit; minify only trims leading/trailing blank lines). Blocks whose content is made up entirely of inline elements (`a`, `span`, `strong`, etc.) are kept on one line so that inserting a newline never introduces a rendered space that wasn't there before. Minification only performs changes that are provably safe: stripping ordinary comments (while keeping conditional comments `<!--[if` and bang comments `<!--!`), fully collapsing whitespace between block-level tags, collapsing runs of whitespace inside text to a single space (never to zero, so words never merge), and trimming leading/trailing whitespace from the whole document. It does not remove optional closing tags, strip quotes from attribute values, or reorder/deduplicate attributes — doing so would rewrite structure you wrote on purpose, which conflicts with this tool's promise to never break your markup. Mismatched or unclosed tags are handled gracefully: the tool never crashes and never silently deletes content, even if it can't fully repair the structure. Everything runs entirely in your browser's JavaScript; nothing is ever sent anywhere.