Fix MHTML to PDF Conversion Issues (2026)
Most MHTML conversion failures are caused by malformed archive metadata, missing assets, or oversized pages. Use this checklist to quickly isolate and fix the issue.
1. Blank preview after upload
If preview stays blank, verify the file is a real `.mhtml` or `.mht` export and not renamed HTML. Try opening the file in a browser first. If it opens there but not in converter preview, use compatibility mode by reloading the file and converting again.
2. Missing images or icons
Missing assets usually mean broken content-location links inside the archive. Re-save the page from the browser to regenerate embedded assets in a consistent structure.
3. Styles look broken in PDF
Some web pages rely on runtime scripts and dynamic CSS. MHTML captures static output, so style changes generated after load may not be preserved. Capture the page only after all animations and lazy sections complete.
4. Conversion fails on large pages
Very large captures can hit browser memory limits. Split long pages into smaller sections where possible or retry with fewer heavy media blocks.
5. Download is available but preview seems unchanged
This usually means fallback conversion succeeded while in-page rendering failed. Download the PDF and verify output directly. If quality is acceptable, fallback is working as intended.
Fast diagnostics checklist:
- Confirm extension is `.mhtml` or `.mht`.
- Re-export source from browser if archive is old.
- Retry conversion after page size switch (A4/Letter).
- Check downloaded PDF even if preview is limited.