CSV Column Split / Merge
Keep, reorder or combine CSV columns.
How to use
- 1 Paste your CSV — the first row is treated as the header row.
- 2 Choose Split to keep selected columns, or Merge to combine them.
- 3 Tick the columns you want (selection order is preserved when splitting).
- 4 For merge, set a separator and new header, and decide whether to replace originals.
- 5 Copy the rewritten CSV from the output box.
About CSV Column Split / Merge
CSV Column Split / Merge reshapes the columns of a comma-separated file without spreadsheets or scripts.
It reads the first row as headers, shows each column as a labelled checkbox, and rewrites the data based on what you tick — all live in your browser.
In "Split" mode you choose which columns to keep and the tool returns a CSV containing only those, in the exact order you selected them.
Because order is preserved, this doubles as a quick column reorderer: tick the columns in the sequence you want and the output follows.
It is the fastest way to drop personal fields before sharing a dataset, pull a couple of columns out of a wide export, or rearrange headers to match a target schema.
In "Merge" mode you pick two or more columns and combine their values into a single new column using any separator you like — a space for "first last" full names, a hyphen for codes, or a comma for addresses.
You can name the new header and choose whether to append it at the end or replace the original source columns in place.
Quoting follows the usual CSV rules, so values that contain commas, quotes or newlines are escaped correctly.
Everything runs client-side: your data is never uploaded, logged or stored, which makes it safe for confidential exports, and it keeps working offline once the page has loaded.
FAQ
Can I reorder columns, not just drop them?
Yes. In Split mode the output columns follow the order you select them in, so ticking columns in a new sequence reorders them.
How are commas inside a field handled?
Parsing and output both follow standard CSV rules, so fields containing commas, quotes or newlines are quoted and escaped correctly.
Is my data uploaded anywhere?
No. All parsing and rewriting happen locally in your browser. Nothing is sent over the network or stored.