XLSX to MHT Converter
Processing entirely on your device — large files may take a moment.
XLSX is the modern Microsoft Excel workbook format. It stores multiple sheets with values, styles and charts, and opens in Excel, WPS Office, Numbers and Google Sheets. Convert MHT archives to PDF for clean printing, or extract the readable document from a saved page.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How XLSX compares to MHT
| XLSX | MHT | |
|---|---|---|
| Structure | Multiple sheets | Tag semantics |
| Best for | Finance, analysis, models | Web pages and shareable documents |
How to convert XLSX to MHT
- 1
Select your files
Drag & drop your XLSX files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to MHT". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted MHT file individually, or grab everything at once as a ZIP archive.
About the XLSX format
XLSX is the modern Excel workbook (default since Excel 2007, same OOXML zip-package idea as DOCX). One file can carry multiple sheets, typed cells, formulas that recalculate, charts, conditional formatting and pivot caches — a small application, not just a table. LibreOffice, Google Sheets and WPS open it natively, and server-side libraries can read and write it without Excel installed.
Being a spreadsheet program's file, it is a poor plain-data exchange format: formulas reference cell positions that break when rows are reordered, hidden sheets and cached values surprise consumers, and the zip package is heavier than CSV. For analysis and finance it is the right tool; for pipelines, export the CSV.
+ Strengths
- ✓Multi-sheet with formulas, charts and formatting
- ✓Typed cells and recalculation
- ✓Opens natively across the office ecosystem
! Limitations
- −Heavier and less diff-friendly than CSV
- −Formulas tie data to cell positions
- −Hidden state (sheets, caches) surprises downstream tools
About the MHT format
HTML is the markup language of the web itself. A document is plain text decorated with tags that describe structure — headings, paragraphs, lists, links, tables, images — and browsers turn that structure into a rendered, styled page. It is both a format and a program target: CSS styles it and JavaScript makes it interactive.
As a document format, HTML's strength is universality: any device with a browser displays it, text stays selectable and searchable, and links make it navigable. Its weakness is that rendering depends on the surrounding CSS and viewport, so it is a flowing document, not a fixed-layout one — printing or archiving an HTML page is inherently an approximation.
+ Strengths
- ✓Displays on every device with a browser
- ✓Semantic structure: headings, links, tables, media
- ✓Text remains selectable, searchable and accessible
! Limitations
- −Final look depends on CSS and viewport
- −Not a fixed-layout or print format
- −Untrusted HTML must be sanitized before display
Why convert XLSX to MHT?
Converting makes sense where the strengths of MHT meet what XLSX cannot give you. Displays on every device with a browser Meanwhile Heavier and less diff-friendly than CSV One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this XLSX to MHT converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
What about special characters and non-English text?
Everything is handled as UTF-8. When you export CSV for Excel, a UTF-8 BOM is included automatically so Chinese, Japanese, Korean and accented characters display correctly on both Windows and macOS.
Are formulas, styles or multiple sheets converted?
No — this conversion extracts the data itself into MHT. Formulas are exported as their current values, styling is not carried over, and multi-sheet workbooks convert sheet by sheet. For full fidelity between spreadsheet formats, exchange within the same tool family.
How large can my XLSX file be?
Since everything runs locally in your browser, the real limit is your device memory rather than an upload cap. Files up to a few hundred megabytes are usually fine on a modern computer; extremely large ones simply take longer.