EXCEL TUTORIAL · FREE TOOLS
Contents
Rename CSV Columns Online
Free online tool · No signup · Runs in your browser
Rename CSV headers using explicit source-to-target mappings.
Your data stays in this browser tool. No account or upload to a processing service required.
Instructions
- Paste a table with unique headers.
- Enter Source -> Target on each mapping line, then click Map column names.
- Review and download the renamed table.
Understanding your result
Mapping Name -> Full Name renames that sample heading while retaining Alice and Bob underneath it. Map every heading your destination expects, then compare the downloaded first row with its import template. Renaming a field does not convert the data stored below it.
What to do if you have a problem
If a mapping fails, check the source header's capitalization and spaces. Give each target a unique name. If the destination also requires a new column order or different date format, prepare those explicitly rather than assuming a header rename handles them.
What to know before using the result
Maximum 2 MB and 20,000 rows including the header. Header matching is exact and case-sensitive. Unknown or repeated sources and duplicate target names are rejected. Unmapped columns retain their names. Each row must have the same width. Header names cannot contain the mapping separator ->.
These tools work with pasted text or supported CSV files rather than Excel workbook files. CSV exports contain values and do not preserve workbook formatting, formulas or multiple worksheets. Formula builders produce formula text to use in Excel. Data processing runs in the browser tool.
Try an example
Name,Age,City Alice,32,Dublin Bob,24,Cork
Summary
Download the renamed headers and compare them with the destination's required field names.