Paste HTML or CSS — it formats as you type. Auto-detects language, numbers lines, highlights syntax on input and output, flags unsupported syntax with the exact line, and supports Format, Lines, and Minify modes — with a before/after fidelity check to prove nothing was silently lost.
Re-parsing the output and minifying it produced different content than minifying the input directly — not just reformatted, something was actually added, dropped, or changed.
Re-parsing the output and minifying it produces exactly the same content as minifying the input directly — this diff below is whitespace/indentation only.
Parses HTML or CSS into a lightweight tree with live syntax highlighting, gutter line numbering, and markup validation. Safely preserves dynamic template expressions (like Shopify/Liquid {{ ... }} and {% ... %}) and nested at-rules like @media, then re-renders according to your chosen action:
Content inside <pre>, <textarea>, <script>, <style> and <code> is preserved verbatim, and the syntax validator inspects for mismatched tags, unclosed braces/parentheses/quotes/comments and duplicate attributes — each finding points at the exact source line, shown as a dot in the gutter you can hover for the message.
Before/after diff re-parses the formatted output and minifies it, then compares that canonical form against minifying the input directly — proving the parser understood the same structure both times, not just that the renderer is consistent with itself. A whitespace-only text node between two inline elements (<b>A</b> <i>B</i>) is kept as a real space since dropping it would visibly run the words together; the same whitespace between two block-level elements is dropped, since that's what a browser does with it either way.
Parsing, validation and formatting happen entirely in your browser. Nothing you paste is uploaded.
