Use the Rows and Columns Converter for a specific table change
This page helps you reshape a wide table into identifier, field, and value rows, or rebuild a wide table from that long representation. It is useful when a spreadsheet export, database extract, analytics file, or command-line result has the right values but the wrong table shape. Paste a representative sample first or choose a local CSV, TSV, or text file. The source stays unchanged in the input area, and the transformed result appears separately for review.
A wide sales table might contain Store, January, February, and March. Use Store as the identifier to produce Store, Field, and Value rows; reverse the layout by naming the ID, key, and value columns. Start with a few rows whose values you already know. A small example makes it easier to confirm field boundaries and row counts before processing a larger table. The page does not upload the source or result to NexaCurrent.
Choose delimiters, headings, and the operation
Wide to long accepts one or more identifier headings on the first instruction line, followed by optional names for the field and value columns. Long to wide accepts exactly three headings: ID, key, and value. CSV, tabs, semicolons, pipes, and one-character custom delimiters share the same quoted-field rules. A delimiter inside a quoted value remains part of that value, doubled quotation marks become one quotation mark, and a line break inside quotes remains inside the cell.
Tell the page whether the first row contains headings. With headings, you can select a unique column by name; a position such as #2 always selects the second column and is required when headings repeat. Without headings, generated positions keep the operation explicit. The page stops on inconsistent row widths instead of shifting later values into the wrong fields.
Read the preview and recipe before downloading
In wide-to-long mode, multiply each source record by the number of measure columns. In long-to-wide mode, verify that every distinct key becomes one heading and every ID remains one row. The result area displays the selected operation, heading policy, source and destination delimiters, and safe-export choice. It previews no more than thirty lines so a large paste does not create an enormous page, while Copy and Download use the complete validated result.
Undo result removes the current transformation without changing the pasted source, which lets you revise one setting and try again. Reset workspace clears the source, selected file, instructions, result, warnings, and download, then restores comma input, comma output, heading mode, and safe export. Downloads use CSV for commas, TSV for tabs, and plain text for other separators.
Handle spreadsheet formulas and malformed rows safely
Spreadsheet programs can interpret text beginning with =, +, -, or @ as a formula when a delimited file is opened. Safe export is enabled by default and adds a visible apostrophe to such cells. The warning reports how many cells changed. Turn it off only when the destination treats every field as plain data and you intentionally need the original first character.
An empty source, an unclosed quote, text after a closing quote, an unexpected quotation mark, mismatched row widths, an invalid custom delimiter, or an unavailable column produces a visible error and no download. A new failed attempt clears an older result so it cannot be mistaken for fresh output. Duplicate headings remain visible and must be addressed with numbered positions.
Limits, privacy, and a practical final check
Long-to-wide conversion stops when the same ID and key occur more than once because choosing one value would discard evidence. Aggregate or de-duplicate those records explicitly before trying again. Input is limited to 1,000,000 characters, 20,000 data rows, 200 columns, and 200,000 cells so an accidental paste cannot exhaust the tab. Files above that boundary should be processed with a streaming desktop or command-line tool. Browser memory can also be tighter on a phone, so use a desktop for large tables.
Before replacing an import file, compare record and column counts, inspect empty and multiline values, search for a known first and last record, and open a downloaded copy in the intended application. Keep the original until the destination accepts the result. A successful transformation confirms the rules shown on this page; it cannot verify a private schema, business rule, access policy, or downstream calculation.