CSV Column Extractor
Pick the columns you want out of a CSV, reorder them, drop duplicate rows and filter by a value, then export the result as CSV, TSV or JSON without opening a spreadsheet.
Last reviewed by the Radiatus Cloud team
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The export always has too many columns
A CRM export, an analytics download or a database dump arrives with sixty columns when the task needs four. Opening a large file in a spreadsheet to delete columns is slow, risks reformatting dates and identifiers, and produces a file with a byte order mark and localised separators that the next tool refuses to read. Trimming the columns before the data ever reaches a spreadsheet avoids all of it.
What column selection should also do
Selecting columns is rarely the only step. The same task usually includes reordering so the key column is first, dropping rows that are exact duplicates once the extra columns are gone, and filtering to the subset you care about. Doing all of that in one pass matters because each round trip through a spreadsheet is another chance for an identifier to be reformatted as a number in scientific notation, which is the single most common way a CSV pipeline silently corrupts data.
Output format is part of the job
The trimmed data often needs to go somewhere specific: a tab separated file for a bulk import, JSON for an API, or CSV again with a particular delimiter. Producing the right shape at the end of the extraction saves a second conversion step, and it means the quoting is applied once by something that follows the RFC rather than by whatever the spreadsheet decided to do.
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Frequently Asked Questions
Does it preserve leading zeros and long numbers?
Yes. Everything is treated as text from parse to export, so a postcode of 01234 stays as typed and a sixteen digit identifier is not converted to scientific notation. That conversion is a spreadsheet behaviour, not a CSV one.
Can I reorder the columns?
Yes. The output follows the order you select them in, and you can move a column with the arrow controls. The header row is rewritten to match.
How does duplicate removal work?
It compares the selected columns only, after extraction. Two rows that differed solely in a column you dropped become duplicates, which is usually the intent when reducing an export to a distinct list.
What does the filter accept?
A plain substring or a regular expression, applied to a chosen column. Rows that match are kept, or excluded if you invert the match. The row count before and after is shown so an over aggressive filter is obvious.
Is the file uploaded?
No. Parsing, filtering and export all happen in your browser, which is the point: exports of this kind usually contain customer records.
Privacy & Security
Everything runs in your browser; nothing is uploaded.
How to Use
Paste a CSV, tick the columns you want to keep, and copy or download the trimmed result.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
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