Manage Columns in CSV Files Online
Drop or select specific columns from CSV files directly in your browser. No upload required.
How to manage Columns in CSV files
- Drop your file onto the upload area. Every column is listed as a chip with its detected type, and all are selected to start with.
- Click a chip to deselect a column you want to drop. It turns grey with a line through it. Click again to bring it back.
- Use Deselect all and then click the few columns you need when you only want to keep a handful.
- Click Apply to preview the result, then Download to save it in the same format you uploaded.
Your file is processed locally in your browser and is never uploaded. The free limit is 50 MB per file; larger files work if your device has the memory for them.
Worked example
An HR analyst needs to send a headcount list to a facilities team, without salary or national ID numbers.
Input (CSV)
emp_id,name,dept,salary,national_id
2041,Maria Keane,Finance,68000,KX 44 91 02 C
2042,Dev Patel,Operations,54500,LM 20 17 88 A
2043,Sofia Brandt,Finance,71200,PR 63 05 19 DSettings
- Deselected: salary, national_id
- Kept: emp_id, name, dept
Result
| emp_id | name | dept |
|---|---|---|
| 2041 | Maria Keane | Finance |
| 2042 | Dev Patel | Operations |
| 2043 | Sofia Brandt | Finance |
The two sensitive columns are removed entirely, not blanked, so they are absent from the downloaded file. The three kept columns stay in their original left-to-right order with their original types. Every row is kept, and no values change.
Working with CSV files
Dropping columns is the fastest way to make a wide CSV export manageable. A 60-column dump from a CRM or ERP often needs only six fields for a given job, and the smaller file opens faster and is easier to diff. Because the file is fully parsed first, a column that holds commas or line breaks inside quotes is removed cleanly, which cutting by position with a text editor or cut -d, often gets wrong. Each chip also shows the type detected for its column, a quick sanity check before you drop anything.
The header is written back with only the kept column names, in their original order. Values in kept columns are written as parsed: numbers without formatting, dates as YYYY-MM-DD, and blanks as empty fields. When a CSV has duplicate header names, the second one gets a numbered suffix on load, so you can keep or drop each one separately. The row count never changes, only the width of the file.
Frequently Asked Questions
Is this safer than deleting CSV columns in a text editor?
Yes. The file is parsed properly first, so commas and line breaks inside quoted values do not shift data into the wrong column.
Can I keep only two columns from a wide CSV?
Yes. Click Deselect all, then click the two columns you want, and Apply.
Can I reorder columns with this tool?
No. Kept columns stay in their original left-to-right order. To change the order, use the SQL Query tool and list the columns in the order you want.
Does selecting columns change any values or types?
No. Kept columns are copied exactly, with the same types. Only the dropped columns are removed.
Can I drop every column?
No. At least one column must stay selected, and Apply is disabled until one is.
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