XLSX ⇄ CSV / JSON Converter
About XLSX ⇄ CSV / JSON
XLSX ⇄ CSV / JSON bridges Excel workbooks and developer-friendly text formats without sending spreadsheet contents to a server.
How it works
Workbook to text
Upload an XLSX file, choose CSV or JSON and optionally identify a worksheet by name or 1-based position. If no selector is supplied, the first worksheet is used.
Text to workbook
Swap direction to parse CSV rows or a JSON array of objects or arrays. The selected sheet name is sanitized to Excel's naming rules before a compressed XLSX file is created.
Binary-safe downloads
Workbook uploads are read as raw bytes and generated workbooks are downloaded as real XLSX binary files, not text disguised with an .xlsx extension.
Frequently asked questions
Are formulas evaluated?
No. The converter reads stored worksheet values and does not run Excel's calculation engine or macros.
Can I choose a worksheet?
Yes. Enter its case-insensitive name or a 1-based index when converting from XLSX.
Is my workbook uploaded?
No. Parsing, generation and download all happen in your browser.
Sources & last verified
The behaviour of this tool and the claims on this page were checked against the specifications below on . Everything runs in your browser, so the output you see is exactly what the engine produced.
Found a wrong result or an outdated claim? Report an error and it will be re-verified.