Tabular
Deduplicate CSV
Paste a table and drop later rows that match an earlier row. Compare the whole row or named key columns.
Input is processed in your browser. DataToolMage does not upload it, store it, or send it to analytics.
Paste structured data. Work stays in this browser.
How it works
Rows are parsed, optionally trimmed, then hashed by the selected cells. The header is preserved.
Input and output
Input is delimited text. Output is delimited text with duplicates removed.
Common uses
Full row
Two identical lines become one.
Key column
Keying on email keeps the first record per email even if other cells differ.
How to use this tool
- Paste CSV.
- Optionally name key columns.
- Copy the unique rows.
Limitations
- Not a fuzzy match or phonetic dedupe.
- Not a file-compare view of two tables.
- Case folding is optional and exact otherwise.
Questions
- Which duplicate is kept?
- The first row in file order. Later matches are dropped. This is not a merge of cell values.
- Can I key on one column?
- Yes. Enter header names to compare only those columns. If a name is missing, the tool errors instead of guessing.
Related tools
CSV Cleaner
Clean a messy export: trim whitespace, drop empty rows, and drop columns that are empty in every row.
CSV to JSON
Paste a delimited table and get an array of objects. Delimiters can be detected. Type inference is optional and conservative.
JSON to CSV
Paste objects and get a table. Column order follows first-seen keys. Nested values are serialized as JSON text, not silently dropped.