Remove duplicates from CSV / Excel
Paste a CSV, TSV, or text dump. Pick which columns define a duplicate. Get cleaned data back — copy-paste ready or downloaded as a fresh CSV.
Deduplicated output
About removing duplicate rows
The Excel "Remove Duplicates" button works fine for simple cases but stalls on big sheets, doesn't handle CSV imports cleanly, and ignores case sensitivity by default. The Qaynaq Labs CSV Duplicate Remover handles paste-text input from any spreadsheet or database export, auto-detects the delimiter (CSV, TSV, semicolon, pipe), and lets you choose which columns define a duplicate — not all of them, just the ones that matter.
Everything runs in your browser. The pasted text never leaves your device. Output is copy-paste ready as TSV/CSV or downloadable as a fresh file. Handles common gotchas: quoted fields with embedded commas, escape-sequence quotes, trailing whitespace, case-sensitivity toggle.
Frequently asked
What's the maximum data size?
Practically limited by browser memory. Tested up to ~500k rows on a laptop. For multi-million-row sheets, use a database or pandas.
Will it handle quoted fields?
Yes — single-line quoted fields with embedded commas and escaped quotes work. Multi-line cells (newlines inside quotes) aren't supported in v1.
Why don't I just use Excel's Remove Duplicates?
You can. This tool wins when (1) data isn't yet in Excel, (2) you want to dedupe on a subset of columns easily, (3) you want case-insensitive matching, (4) the sheet is big enough that Excel hangs.
Can it dedupe across multiple files?
Not directly — paste them concatenated. The first row of each file is treated as a data row if you uncheck 'First row is header'.