Text tool

Duplicate Line Remover

Remove repeated lines while preserving the first occurrence and original order.

Use the tool

Privacy-first: this tool runs in your browser. Your input is not sent to ToolsDiary unless the page explicitly says otherwise.

What this tool does

Deduplicate newline-separated lists such as keywords, URLs, usernames, IDs or inventory labels. You can choose case-sensitive or case-insensitive matching and optionally trim whitespace before comparison.

Deduplication is simple until small differences such as capitalization or trailing spaces make identical-looking entries behave as different values. This tool lets you control those decisions explicitly and reports how many lines were removed.

Useful for

  • Clean keyword or hashtag lists.
  • Remove repeated URLs before batch processing.
  • Deduplicate copied IDs, names or labels while preserving order.

How to use it

  1. Paste one item per line.
  2. Choose whether matching should ignore capitalization and surrounding spaces.
  3. Run the deduplicator.
  4. Review the removed-count summary and copy the cleaned list.

Practical tips

  • Use case-sensitive matching when capitalization carries meaning.
  • Trimming whitespace is helpful for human-entered lists.
  • For structured CSV data, use a spreadsheet or database tool instead of treating whole rows as plain text.
  • Nothing is uploaded to ToolsDiary.

Frequently asked questions

Does the tool sort the list?

No. It preserves the order of the first occurrence of each unique line.

Can blank lines be removed?

Yes. You can choose to discard empty lines during cleanup.

What happens to duplicate lines?

Only the first matching occurrence is kept; later matches are removed from the output.