Combine two or more columns in a CSV
To merge columns in a CSV, open the column combiner in Sigmera, tick the columns you want to combine, choose a separator such as a space or comma, name the new column, and preview the result before downloading. Sigmera does this entirely in your browser — your data is never uploaded to a server, so it’s GDPR-safe by design.
Last updated: June 2026
Use the column combiner free in your workspace
Free account, no credit card — every tool, unlimited rows, 3 free downloads a month, nothing uploaded.
🔒 Everything runs in your browser — your file is never uploaded, and the workspace even works offline once it has loaded.
Ways to combine CSV columns, compared
| Method | Data uploaded? | Pick separator | Skill needed |
|---|---|---|---|
| Sigmera (this tool) | No — runs in browser | Yes, one click | None |
| Excel CONCAT / TEXTJOIN | No | Yes, in the formula | Medium (function syntax) |
| Excel “&” formula | No | Manual (type each one) | Medium (formula + drag-fill) |
| Python / pandas | No | Yes, in code | High (code) |
How to combine columns in a CSV
- 1. Drop your CSV into the tool. The file is read into your browser’s memory — it is never sent over the network.
- 2. Pick the columns to combine. Tick two or more columns, such as first_name and last_name. They are joined in the order you click them.
- 3. Choose a separator and name the column. Use a space, comma, dash, underscore, or nothing at all, then give the new combined column a name like full_name.
- 4. Preview and download. Check the new column in the preview, then create a free account to export the full CSV.
Why combine columns?
CRMs and email tools usually want a single field where your export has several — a full_name built from first and last name, or a single address line built from street, city, and postcode. Combining the columns before import means cleaner records and fewer mapping errors. Because Sigmera processes the file locally with the browser’s built-in JavaScript engine, there is no server to upload to and nothing is stored — which satisfies GDPR data-minimization (Article 5) because zero bytes leave the device.
Frequently asked questions
- Does this tool upload my CSV file?
- No. The column combiner runs entirely inside your web browser using client-side JavaScript. Your file is never uploaded to a server and never leaves your device, so it is GDPR-safe by design.
- Can I join more than two columns?
- Yes. Select as many columns as you like — first name, last name, and a suffix, or street, city, and postcode. They are combined in the order you click them, and any empty cells are skipped so you never get stray separators.
- What separators are supported?
- You can join with a space, a comma and space, a dash, an underscore, or no separator at all. A space is the default, which is what you usually want for building a full name from first and last name.
- Can I do this in Excel with TEXTJOIN?
- Yes — Excel's TEXTJOIN and CONCAT functions, or the classic "&" formula, all merge cells into one. They work, but you have to write the formula, get the argument order right, and then paste-as-values. Sigmera combines the columns with a couple of clicks and no formula.