Column Renamer
Rename CSV headers in bulk with old:new mapping — standardize client exports fast. Fix 40 messy columns before import — local parsing, free, no signup.
How to Use the Column Renamer
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Frequently Asked Questions
How does the mapping work?
Enter comma-separated old:new pairs (name:full_name, role:job_title) — headers rename in one pass. Unmapped columns keep original names, so partial maps are safe.
What about duplicate new names?
Duplicates are not flagged — mapping two columns to the same new name produces two identical headers. Rename or drop one side first.
Does data change too?
No — only header row rewrites; all rows pass through byte-identical. Verify with a diff on the first run.
Is my CSV uploaded?
No — parsing runs locally in your browser. Data never leaves your device.
Can the new name contain a colon?
No — mappings split on colons and keep only the first two parts, so a mapping like time:12:30 renames the header to 12, dropping the rest. Unmatched headers pass through unchanged, so partial maps are safe.
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Last updated October 2026