HTML Minifier collapses meaningful whitespace inside <pre> and <textarea>

[baixiangcpp]

Summary

HTML Minifier removes meaningful whitespace inside elements whose text content is whitespace-sensitive. This changes the rendered/content value instead of only removing formatting between tags.

Reproduction

1. Open https://byteflow.tools/en/html-minifier.
2. Paste:

<pre>  a   b
  c  </pre>
<textarea> x  y </textarea>
<div>  spaced text  </div>

3. Click Minify.

Actual output

<pre> a b c </pre><textarea> x y </textarea><div> spaced text </div>

The two spaces, repeated spaces, and newline inside <pre> are lost. The repeated space inside <textarea> is also lost.

Expected output

Whitespace inside <pre> and <textarea> should be preserved, while whitespace between tags may be minified. For example:

<pre>  a   b
  c  </pre><textarea> x  y </textarea><div> spaced text </div>

Impact

Minifying markup containing code samples, preformatted text, or user-editable textarea content changes the content semantics and can corrupt the displayed or submitted value. The page documentation also says to preserve semantics in <pre>, <code>, and inline text.

Environment

• Tool: HTML Minifier
• URL: https://byteflow.tools/en/html-minifier
• Observed: 2026-08-18