CSV & Text List Deduplicator

Remove duplicate rows or items from CSV datasets, email lists, and text files with A-Z, Z-A, or original order preservation and case-sensitivity controls.

Category: File & Data

How to Use CSV & Text List Deduplicator

  1. Paste your CSV rows, email list, or line-separated text into the input editor.
  2. Choose your preferred Sort Output Order (Alphabetical A-Z, Reverse Z-A, or Preserve Original Order).
  3. Toggle Case Sensitive Matching depending on whether 'Item' and 'item' should be treated as distinct.
  4. Click Process to generate the deduplication metrics report and copy the clean unique list.

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Frequently Asked Questions

How does the CSV & Text List Deduplicator identify and remove duplicate rows?

The engine scans your input line by line using a hash-set lookup (`Set`). It records the normalized signature of each line on first encounter and strips any subsequent identical lines in O(n) linear time.

What happens when Case Sensitive Matching is disabled versus enabled?

When Case Sensitive Matching is disabled (the default), 'Apple', 'apple', and 'APPLE' are treated as duplicates; the tool retains the exact casing of the first occurrence ('Apple') and removes the rest. When enabled, 'Apple' and 'apple' are preserved as distinct entries.

Can I deduplicate a list while keeping the original row order intact?

Yes. Select 'Preserve Original Order' in the Sort Output Order menu to keep every unique line in the exact sequence it first appeared, which is essential when header rows must remain at the top of a CSV.

Does the deduplicator report how many duplicate lines were removed?

Yes. Every run generates a header summary showing the Original Item Count, exact Duplicates Removed count, Unique Item Count, and active sort mode, while the 'Copy Formatted Syntax' button copies only the clean unique list.