Rename or Reorder CSV Columns in the Browser: What the Export Actually Contains

The Data Studio in OnePassApps has eleven tool tabs. Nine posts on this site cover ten of them; the Columns tab had never had one, so that is today's post: the one place where you pick a column, rename it, move it left or right, and then check what the exported file actually contains.

I work on OnePassApps.

You can try it at the Data Studio. The written walkthrough is on the OnePassApps guides page.

Before you load anything

The panel is the usual three steps - 01 Source, 02 Options, 03 Result - and the action button on this tab is "Load / refresh columns", not "Parse CSV". The options step is empty until you press it, and the panel tells you so: "Column options appear once the CSV is loaded."

The preview area reads "CSV PREVIEW" with "No data yet", and the stage hint says "Load the columns, then rename or reorder them in Options." The source hint is the Data Studio's usual one: "Drop a data file, or browse CSV, TSV, JSON or YAML · up to 20 MiB · or paste rows in Source".

The four controls that appear

After the load, 02 Options holds four things:

• Delimiter - the same picker as everywhere else, shipping on "Auto detect · comma", with Comma, Tab, Semicolon and Pipe behind it.
• Column - a picker whose options are your real header names. On a six-column file it offered id, name, score, active, note, price.
• Position - two arrow buttons, "Move column left" and "Move column right".
• Rename column - a text input, prefilled with the selected column's name, with a Rename button beside it.

Renaming a column, and reading the export

Pick name, clear the rename field, type employee_name, press Rename. The result step reports "Column name updated in the active table." The preview header changes with it - the column now reads employee_name with a TEXT badge - and so does the exported file.

The "Download CSV" button on this tab writes a real file. After the rename it was 169 bytes of text/csv;charset=utf-8, and its header row was:

"id","employee_name","score","active","note","price"

Moving a column

With the first column selected, "Move column left" is disabled - there is nothing to its left. "Move column right" moved id one slot along: the preview became name, id, score, active, note, price, and the downloaded file was 160 bytes with the header

"name","id","score","active","note","price"

To move a column a longer way, select it in the picker (the last column, price, is fine) and press "Move column left" as many times as you need. Two clicks on price gave name, id, score, price, active, note, and the file matched:

"name","id","score","price","active","note"

Rename and reorder in the same pass

The two controls are independent, and the export carries both. After renaming the moved column from price to amount, the preview read name, id, score, amount, active, note and the downloaded file was 161 bytes:

"name","id","score","amount","active","note"

What the bytes keep

Every field is quoted, the line endings are CRLF, and the values are untouched: a cell holding 007 was still "007" in the export, so nothing was coerced to a number, and the empty cell was an empty quoted field rather than the em dash the preview shows. The preview's type badges (id NUMBER, score NUMBER, the rest TEXT) are a label for the eye - the export does not convert anything on the strength of them.

The caveat worth knowing

"Reload CSV" re-reads the source you pasted. After I renamed a column and then pressed it, the rename was gone and the header was back to its original name, while the counts were unchanged - "Loaded 3 rows and 6 columns.", "3 rows · 6 columns · no parsing issues", "Delimiter found Comma". The rename lives in the active table inside that tab, not in your file, so export before you reload.

What leaves the tab, and what it costs

Nothing, as usual. The page says "Nothing leaves this tab." and the stage says "Processing stays in this browser.", and the limits box spells it out: "Pasted text supports up to 10,000 lines. Pasted CSV supports up to 8 MiB and 10,000 data rows; CSV files support up to 20 MiB, 100,000 rows, and 2 million cells. JSON supports up to 2 MiB and YAML up to 1 MiB. Your data stays on this device."

The plan block on the same page still reads FREE PROMOTIONAL PERIOD - Standard is free right now, $0 / month, 100,000 credits every 30 days, No end date set, No card required, and No automatic paid subscription.

If you want the same treatment for the other Data Studio tabs, the guides are linked above. I work on OnePassApps - the studios process the file in the tab, not on a server.