Exact report, root cause, and DOM impact
How to Audit HTML
Preserve the complete Nu HTML Checker report, separate document errors from checker failures, and map repeated messages to shared templates.
Audit steps
- Check the exact canonical public URL with the WHATWG-recommended Nu HTML Checker.
- Record final URL/status/MIME and confirm the checker did not receive a redirect, block, login, or error page.
- Save the full report and separately count error/fatal, warning/info, and non-document errors.
- For every message, preserve text, line/column/extract, URL, and probable source template.
- Compare server HTML with parsed/rendered DOM for nesting/parser errors.
- Repeat homepage and one representative URL per template, locale, and edge state.
Classification
| Observation | Level | Action |
|---|---|---|
| Document conforming, checker completed | No issue | Preserve baseline |
| Warning without DOM/UX impact | Verify | Document the decision |
| Content-model/duplicate-ID/invalid attribute | High | Repair shared source |
| Parser tree, broken form/table, fatal, or systemic template error | Critical | Repair and regression-test |
Evidence to save
- Exact URL, final response, checker version/date, and report link/export.
- Counts by message type rather than one mixed total.
- Message text, line/column, extract, and source template.
- DOM/visual/functional impact and template frequency.
- Owner, fix decision, and post-retest report.
Line numbers refer to generated responses and may not match source. Third-party widgets can alter output; WAF/cache/localization may serve another document. Zero errors does not mean accessible, semantic, secure, or SEO-optimized.
Next step
Repair confirmed causes with the guide or use the service with regression testing.
