CSV column picker
Select CSV columns and rearrange their export order with a live table preview.
How it works & useful details
Formats & limits
Import UTF-8 text up to 1.5 MB or paste up to 500,000 characters. CSV accepts comma, tab, semicolon or pipe separators, doubled quotes and line breaks inside quoted fields. All rows must have the same number of fields. A final line ending is ignored; interior blank rows are real rows. A leading UTF-8 BOM is removed. Up to 10,000 rows including the header, 100 columns, 100,000 cells and 50,000 characters per cell. Output is limited to 2,000,000 characters.
Live previews pause above 50,000 input characters; exports still process the full bounded input. The table pages through 15 rows and 12 columns at a time. Export includes every result row. Processing is synchronous and bounded; cancellation is checked before and after a transformation.
Data details
Text comparisons use Unicode code-unit order, with optional case folding. Numeric sorting/filtering requires finite numbers in every selected cell and uses JavaScript decimal precision; large integer identifiers need text mode. No trimming or spreadsheet formulas are evaluated.
CSV-to-JSON defaults to strings. JSON object export requires unique, nonempty headers. JSON input uses object keys in discovery order (integer-like keys follow JSON property order), missing properties become empty cells, and arrays must be rectangular. Primitive arrays get one “Value” column. Null becomes the literal text “null” by default; nested objects/arrays become compact JSON strings. Empty strings, missing values and optional empty nulls are indistinguishable in CSV. Mixed row shapes are rejected. JSON numbers use JavaScript precision; unsafe integers are rejected, so quote large IDs. Duplicate JSON names use the last value.
Transpose allows up to 100 source rows including the optional header, and exports all transposed cells as data. Spreadsheet formula protection is opt-in: it prefixes formula-like cells with an apostrophe, visibly changing their data. Spreadsheet programs differ; review results before opening them.
About this tool
CSV column picker selects a subset of columns and lets you arrange their export order with a live table preview. It is useful when a spreadsheet export contains more columns than a downstream tool accepts.
Everything is parsed locally. The original file is not modified; you choose the columns and download the trimmed CSV.
How to use it
- Import a CSV file or paste the text.
- Select the columns to keep and drag or reorder them into the export sequence.
- Check the live preview of the resulting table.
- Export the trimmed CSV.
Worked example
From a table with the columns Name, Team, Score, Active, picking Score and then Name produces:
Score,Name
92,Ada
84,Lin
76,Sam
92,Ada
88,JoThe export order follows the order you choose, not the original order. That lets you pick and rearrange columns in one step.
Why trim columns before sharing
Exports from CRMs, shops, and analytics tools often carry dozens of columns, some of them personal data such as email addresses, phone numbers, or IP addresses. Sending only the columns a colleague or a vendor actually needs is the simplest form of data minimisation, a core principle of the GDPR. It also makes imports into other systems less error-prone, because many importers expect columns in a fixed order.
Quoted fields that contain commas or line breaks are parsed correctly, so a column is never split in the middle of an address or a note. The output can use a different delimiter, such as semicolons for European spreadsheet software.
Frequently asked questions
Does selecting columns reorder the original file?
No. The original stays untouched; you export a new CSV with the selected columns in your chosen order.
Can I reorder columns without removing any?
Yes. Keep every column selected and change their order to produce a rearranged export.
What are the limits?
Import UTF-8 text up to 1.5 MB or paste up to 500,000 characters, with up to 10,000 rows and 100 columns.
Can I rename columns while picking them?
Not in this tool. Rename header cells in the spreadsheet editor, or edit the first line of the exported CSV.