Skip to content
Tools.Town
250+ free online tools
×3

Find Duplicate Lines

100% Free

Find which lines repeat and how often — with counts. Optionally copy a unique list (first occurrence wins).

Real-time
Client-Side

0 lines · 0 unique · 0 duplicated values

Duplicate report
Duplicate report appears here…
Unique list (first wins)
Unique list appears here…

Embed This Tool

Easy to Embed

Add Find Duplicate Lines to your website or blog in seconds.

  • Responsive design
  • Lightweight & fast
  • No backend required
  • Always up-to-date 
<iframe
  src="https://tools.town/embed/find-duplicate-lines/"
  width="100%"
  height="600"
  style="border:none; border-radius:12px;"
  loading="lazy"
  title="Find Duplicate Lines">
</iframe>

Share This Tool

Share Instantly

Share Find Duplicate Lines with anyone — no login required.

  • Shareable link
  • No login required
  • Works on any device
  • No account needed

Share via

Advertisement

How to Use

  1. 1 Paste your list — one item per line
  2. 2 Review the duplicate report (line × count)
  3. 3 Optionally copy the unique list

Features

  • Shows each duplicated value with occurrence count
  • Sorted by frequency (highest first)
  • Optional unique list (first-wins)
  • Case and trim toggles

Why it Matters

Sometimes you need to see what is duplicated before removing it — audit an export, spot bad merges, then dedupe.

★★★★★

Use Cases

Export audit

See which emails or IDs appear more than once

Then remove

Copy uniques, or switch to Remove Duplicates from List

Frequently Asked Questions

How is this different from Duplicate Line Remover?
This tool reports duplicates with counts. The Remover focuses on outputting a clean unique list.
📖

Want to go deeper?

Browse all guides →
List Ops
list

List Ops — Sort, Dedupe, Split & Clean Lists Online

The Tools.Town List Ops cluster: sort ascending/descending, remove duplicates, split into chunks, compare two lists, and format bullets — free, in-browser.

14 Aug 2026

5 min read

Case-Sensitive vs Case-Insensi
dedupe

Case-Sensitive vs Case-Insensitive Dedupe

When Apple and apple should count as duplicates — and when they must stay separate. Tools.Town dedupe toggles explained.

14 Aug 2026

5 min read

Related Tools You Might Like

Remove Duplicates from List

Remove duplicate lines from any list. Keeps the first occurrence and original order. Case and trim toggles.

Duplicate Line Remover

Strip duplicate lines from any list, preserving the first occurrence and original order. Case + whitespace toggles, optional alpha sort.

Compare Two Lists

Compare two line lists — only in A, only in B, intersection, union, or symmetric difference. Case and trim toggles.

List Splitter

Split any line list into chunks of N, into K equal groups, or by blank lines. Label groups, copy all or one group at a time.

Text Sorter

Sort lines five ways — alphabetical, natural (item2 < item10), length, numeric, random shuffle. Reverse, case toggles, blank-line handling.

Browse more free tools
More Text Tools All categories