HTMLフォーマッター

This is an HTML formatter that beautifies markup with block and inline aware indentation, or minifies it by collapsing whitespace and stripping comments. You pick the indent size when beautifying.

Beautifying indents elements according to how they nest, so the structure of a document, which elements contain which, becomes obvious. That makes hand-written or generated HTML far easier to read and debug.

Both beautify and minify run entirely in your browser, so your markup never leaves your device.

It deliberately leaves the contents of pre, textarea, script and style untouched, because whitespace inside those elements is significant: reformatting them would change preformatted text, what users type, or the meaning of your code.

Minifying removes comments and collapses runs of whitespace, which trims the file size browsers have to download. It is most useful as a build step for production pages.

The minifier keeps a single space between tags rather than removing it entirely, because whitespace between inline elements is actually rendered, and dropping it can shift your layout. This caution avoids the subtle visual bugs aggressive minifiers can cause.