Reviewed 2026-08-28
Format HTML Without Changing Rendered Content
Protect inline spacing, preformatted text, scripts, styles, and templates.
Example input
<p>One <strong>important</strong> line.</p>
Expected output
<p>One <strong>important</strong> line.</p>
Reproducible method
- Preserve the original and create the smallest representative sample.
- Run a strict parse or validation before transformation.
- Record options, compare counts and structure, then test in the receiving system.
Common error
Whitespace changes can alter inline text and preformatted content.
Reduce a failure while retaining the problematic structure; this separates malformed input from unsupported behavior.
Technical limitation
Formatting is not validation or sanitization.
A successful preview does not remove format ambiguity or downstream requirements.
Security and privacy
Never inject untrusted HTML into a preview without sanitizing.
Local processing reduces transfer risk but cannot protect a compromised browser, unsafe extensions, clipboard history, or later misuse.
Verification checklist
- Check field, record, page, or byte counts.
- Review edge cases and error output.
- Retain the original until acceptance.
- Document assumptions for automation.