ToolwebHow to use this tool
- Open CSV, TSV or JSON, or paste data and preview the table. If columns or characters look wrong, choose the delimiter or encoding and preview again.
- Check headers and selected columns. Numeric conversion applies to the whole table; leave it off if even short numeric product IDs must stay text. Inspect preview cell types.
- Set file and sheet names, create and download the XLSX. Reopen it to check leading zeros, long IDs and amount types.
Preserve product codes, order IDs and amount types
- Input and settings
- name,code,amount,order Min,00123,-5,12345678901234567 Jane,00456,12.5,9007199254740993
- Result
- A four-column XLSX. With numeric conversion on, amounts are numeric while product codes and long order IDs remain text.
CSV is text by default. Even with conversion on, codes 00123/00456 keep their zeros and order IDs over 15 significant digits stay text.
Inspect data before creating a workbook
Before moving an order list or a CSV export into Excel, check its columns and encoding. Open a file or paste data using comma, tab, semicolon or pipe delimiters. If automatic detection is wrong, set the options explicitly and preview again. UTF-8, BOM-marked UTF-16 and CP949/EUC-KR are supported.
Use the first row as headers or preserve every row as data. JSON object arrays use the union of object keys as headers, with missing values left blank. Row arrays follow your header setting. Nested objects and arrays become JSON text in a single cell rather than being flattened into columns.
How text and numeric types are chosen
CSV text is preserved by default. Optional safe numeric conversion turns values such as -5 and 12.5 into numbers, while leading zeros, more than 15 significant digits, dates and formula-like text such as =SUM(A1:A2) remain strings. Phone numbers and identifiers often belong as text even when they look numeric.
Native JSON numbers and booleans retain their types where possible. Number lexemes are checked before JSON parsing; values beyond 15 significant digits or the supported range are kept as text instead of being rounded. Numeric preview cells align right, and cell tooltips identify their types.
Output and processing limits
Selected columns and edited headers form one XLSX sheet. Headered tables receive an autofilter range and basic column widths. CSV and JSON have no original Excel formatting, charts or multiple sheets to restore.
Limits are 12 MB, one million characters, 10,000 rows including headers, 100 columns, 50,000 cells and 20,000 characters per cell. JSON nesting is limited to 32 levels. Parsing and writing run in a separate, time-limited worker. Cancelling retains the previous preview. Changed input or reading settings require a fresh preview before exporting.
Text cells and local processing
Values starting with = are stored as string cells, not formulas. No VBA or external connections are created. Input and output remain in this browser tab and are not sent to a server, analytics, the URL or persistent storage. Downloaded XLSX files remain on your device.
Common questions
Will a 16-digit order number change?
Numeric strings with more than 15 significant digits are stored as text. Large unquoted JSON numbers are inspected before JSON.parse and also preserved as text. Converting them back to numbers in another application can lose precision.
Are quoted and multiline CSV cells supported?
Quoted commas and line breaks are supported, with doubled quotes ("") used for embedded quotes. Unclosed or misplaced quotes produce an error so you can check the source.
Can I export selected columns and rename headers?
Use Columns and headers to select included columns and edit header names. Original column order is preserved. Data without a header does not receive a new header row.
Can nested JSON objects become separate columns or sheets?
Nested objects and arrays are kept as JSON text in one cell, and the result has one sheet. They are not automatically flattened or split across sheets. Prepare a flat object array or an array of rows when you need separate columns.