Nirmion
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Developer & Data

CSV Column Mapper

Select, reorder, and rename CSV columns with an explicit source-to-target mapping.

  1. 01Runs in this browser
  2. 02Limits are explicit
  3. 03Copy or download output

Step 1

Set up the source

Add one source=target instruction per line. Only mapped columns appear in the result, in the same order as the mapping.

Confirming the published workspace...

No black box

How this tool handles the input

The CSV is parsed and validated first. Each mapping is matched against the exact header name, then rows are serialized with the new unique headers.

Before you start

What you need

A valid CSV table and at least one exact source=target mapping.

What you get

What the page gives back

A new CSV containing only the selected, renamed columns.

Keep in mind

Use the result responsibly

Header matching is case-sensitive. This tool changes column structure only; it does not transform cell values.

Practical uses

Where this tool earns its place

  1. Align vendor headers with an import template.
  2. Remove unused columns before sharing a file.
  3. Reorder columns for a repeatable handoff.

Verified data boundary

Source text stays on this page.

The published contract marks these tools as client-only processing. Nirmion uses the API only to confirm that this workspace is enabled in MySQL; source values and results are not sent to Flask.

Keep working

JSON to CSVCSV to JSON