CSV Column Extractor
Keep only selected columns and download a new CSV
CSV Column Extractor — what it does
Load a CSV, tick the columns worth keeping and download a new file containing only those fields in the order you selected them. Row order and values are untouched — this is a projection, not a transformation — so the output stays a faithful subset of the source that any spreadsheet or import routine will accept.
When this tool helps
- Cutting an export down to the handful of fields an import template accepts, instead of deleting columns by hand in a spreadsheet.
- Removing personal data such as phone numbers and addresses before sharing a dataset with an outside party.
- Producing a slim file for analysis when the original export carries eighty columns and you need six.
How to use it
- Choose the CSV file to open.
- Select the columns you want to keep.
- Process the file.
- Download the reduced CSV.
Accuracy, limits, and good practice
- Selection order sets output order, so pick columns in the sequence the destination system expects rather than reordering later.
- Fields containing commas or line breaks stay quoted in the output, which keeps the file parseable in Excel and in scripts.
- Dropping a column removes it from this copy only. Keep the original export until the downstream import has been confirmed.
Frequently asked questions
Does the header row survive?
Yes. The header is rewritten with only the selected column names, so the output opens as a normal CSV with labels intact.
What if two columns share a name?
Duplicate headers are ambiguous in CSV. Rename them first with the column renamer so the selection targets the field you mean.
How large a file can it handle?
Files of tens of megabytes are usually fine. The whole document is parsed in memory, so very large exports may need splitting first.
Related tools on this site
- Excel Column Statistics — Calculate count, unique values, sum, average, min, max, and median
- HTML Table to CSV — Extract an HTML table and download it as a CSV file
- CSV Column Reorder — Change CSV column order before downloading
Everything above runs inside this page. CSV Column Extractor needs no account, no upload, and no server round trip — close the tab and nothing is left behind.
CSV 欄位提取能做什麼
載入 CSV、勾選需要保留的欄位，即可下載只含這些欄位、且依你選取順序排列的新檔案。列的順序與內容完全不動——這是投影而非轉換——因此輸出仍是原始資料的忠實子集，任何試算表或匯入程式都能接受。
什麼時候用得上
- 把匯出檔縮減成匯入範本接受的少數欄位，不必在試算表中一欄一欄刪。
- 在把資料交給外部單位前，先移除電話、地址等個資欄位。
- 原始匯出有八十欄、分析只需要六欄時，先產出精簡檔。
使用步驟
- 選擇要開啟的 CSV 檔。
- 勾選要保留的欄位。
- 執行處理。
- 下載精簡後的 CSV。
精確度、限制與實務建議
- 輸出欄位順序依選取順序決定，請直接照目標系統要求的順序點選，省得事後再排。
- 含逗號或換行的欄位在輸出中仍會加上引號，確保 Excel 與腳本都能正確解析。
- 刪除欄位只影響這份副本。在下游匯入確認成功前，請保留原始匯出檔。
常見問題
標題列會保留嗎？
會。標題會改寫成只含所選欄位名稱，輸出仍是帶標題的正常 CSV。
如果有兩欄同名怎麼辦？
CSV 中重複標題本身就有歧義。請先用欄位改名工具區分，再回來選取你要的那一欄。
檔案可以多大？
數十 MB 通常沒問題。整份文件會在記憶體中解析，超大匯出檔建議先拆分。
本站相關工具
- Excel 欄位統計 — 計算筆數、唯一值、總和、平均、最小、最大與中位數
- HTML 表格轉 CSV — 提取 HTML 表格內容並下載為 CSV 檔案
- CSV 欄位重新排序 — 調整 CSV 欄位順序後下載
以上步驟全部在這個頁面內完成，CSV 欄位提取 不需要註冊、不上傳檔案、也不經過伺服器，關閉分頁後不會留下任何資料。