CSV Tools
CSV Header Renamer
Rename CSV column headers with a simple old=new map.
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What is Rename Headers?
A header renamer: paste CSV, write old_name=new_name lines, and get the CSV back with renamed columns and all data intact.
How it works
Each mapping line is parsed into an old→new dictionary, and rows are re-keyed through it before re-serializing.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Normalizing column names
Rename messy headers like 'FIRST_NAME ' and 'email addr' to clean, consistent names in one pass across the whole file.
Common mistakes
Off-by-one header edits
Renaming shifts every column if the mapping is misaligned — the tool previews the header map against the data before applying.
Frequently asked questions
Can I rename several columns at once?
Yes — define the full mapping first, review the preview, then apply to all rows at once.
Does it change the data itself?
No — only the header row changes; all values stay untouched.