Duplicate Column Detector
Paste a CSV file or header row to group repeated column names and names that differ only by case, spaces, or punctuation.
Exact duplicate groups
Near-duplicate groups
No duplicates found in the header.
All header columns
A QUICK WALKTHROUGH
How to use this tool
- Paste CSV text; only its first logical record is analyzed as the header.
- Review exact duplicates and near-duplicates in separate groups.
- Download a plain-text report if you want to share or save the findings.
Header record only
The detector reads the first CSV record, including quoted commas, escaped quotes, and line breaks inside quoted fields. Data rows after that record are ignored.
Two matching levels
Exact duplicates compare trimmed names without case. Near-duplicates also remove whitespace and punctuation, so Email and E-mail are grouped. Column positions and original names remain visible.
Local processing
CSV parsing, grouping, and report generation happen in this browser. The input is not uploaded or saved.
GOOD TO KNOW
Common questions
Does it inspect data rows?
No. Only the first logical CSV record is treated as the header.
How are near-duplicates detected?
After trimming and case-folding, whitespace and punctuation are removed. Symbols and letters remain, so the tool does not guess semantic similarity.
Does it modify the CSV?
No. It only reports matching header names and can download a plain-text report.