Data file converter

Convert a file

1. Choose a local file or paste text. Use the input-format selector if the file has an unusual extension.
2. For Excel, choose one worksheet. For JSON, select the collection containing your records. Review the included fields.
3. Choose an output format, check the preview, then download or copy the result. Excel files are download-only; choose a text format to copy the data.

For example, paste a CSV containing id,name followed by 001,Asha. JSON output keeps the ID as the string "001". Markdown output creates a table with an ID column and a name column.

Export a Markdown table

Choose Markdown table to copy the result into a README, wiki or document. The output includes a header row and separator row. Pipes, backslashes and Markdown punctuation inside cells are escaped. HTML-like text is escaped, and cell line breaks become <br>. Markdown renderers may collapse repeated spaces and tabs. The table preview shows cell content; open Markdown source preview to see the generated markup.

Choose JSON records

A JSON array becomes a set of records. If an object contains several arrays, choose the one you need. Nested objects become named columns such as customer.name. Arrays remain JSON values in JSON output and become JSON text in table formats. Output field names describe the flattened table; the original nested document structure is not rebuilt.

JSON number tokens keep their exact digits in CSV, TSV, JSON and Markdown. Excel exports those numbers as text cells to avoid rounding. CSV and TSV values remain strings in JSON output. JSON booleans and null retain their types. Missing fields are omitted from JSON objects and become empty cells in table formats.

Privacy and limits

Files, pasted text, selected fields and results remain in browser memory. The tool does not upload them, save them in browser storage or include them in URLs. Clear all data clears the input and results. Reloading clears tool data. Only the shared theme preference is saved. Copy writes to the clipboard only when selected. Download saves a file to your device. See privacy and analytics.

Inputs allow 5 MiB. Selected data allows 20,000 rows, 100 fields, 500,000 cells including headers and 20 million characters. Output is limited to 20 million characters, or 20 MB for Excel. Field names allow 200 characters, including nested JSON paths. JSON allows 40 nesting levels and 500,000 values. Excel ZIP archives allow 25 MiB of declared expanded content and 2,048 entries. Parsing stops after 20,002 worksheet rows and rejects oversized worksheet ranges. Distant formatted cells can count towards a worksheet’s range.

Text files must use UTF-8. CSV uses commas and TSV uses tabs; quoted fields, embedded line breaks and doubled quotes are supported. Blank physical lines are skipped. Uneven rows and malformed quotes are rejected. Header cleanup gives blank, duplicate or padded names unique trimmed names, with a warning. JSON duplicate field names are rejected. JSON Lines requires one complete JSON value per nonblank line.

Excel input supports .xlsx and binary .xls workbooks. Export creates one .xlsx worksheet of values. Formulas use saved results and are never recalculated. Formulas without saved results block conversion. Styles, images, charts and macros are not copied. Displayed text preserves saved number formats; underlying values expose numeric date serials. Merged cells keep their top-left value. Excel cells allow at most 32,767 characters. Password-protected workbooks and Parquet are not supported.

Hosted processing runs in a background browser worker with a 20-second limit per operation. Clear all data cancels processing. Direct local-file use runs on the page and can briefly pause. A failed load clears the previous data and result. Clipboard access may require HTTPS or permission. Modern browsers with File.arrayBuffer(), TextDecoder, TextEncoder, workers and Blob URLs are required.

Excel support uses a locally bundled copy of SheetJS Community Edition, under the Apache 2.0 licence.