How to Find Duplicate Lines in Text With Counts
To find duplicate lines in text, paste your list into a duplicate-line finder and it lists every line that appears more than once along with the exact number of times each one occurs. ByteTools does this instantly in your browser, with an optional case-insensitive mode, and it never uploads your data.
Duplicates hide in mailing lists, exported spreadsheets, log files, and copy-pasted data. Finding them by eye is impractical past a few dozen rows. This guide shows the fast, reliable way.
What the tool does
Paste any text with one item per line and it scans for repeats. Unlike a tool that simply strips duplicates, this one reports them: it shows you which lines recur and how many times, so you can understand the problem before deciding what to do about it. A summary tells you how many duplicate values were found overall.
Enable case-insensitive matching and lines that differ only in capitalization — Apple and apple — are treated as the same value and counted together.
Step-by-step
- Paste your text into the input box, one entry per line.
- Choose case sensitivity. Leave it off to treat different capitalizations as distinct, or turn on case-insensitive matching to merge them.
- Review the results: each duplicated line appears with its occurrence count.
- Copy or download the duplicates report for your records or your next step.
Reading the results
| Input lines | Duplicate reported | Count |
|---|---|---|
| alice@x.com (×3) | alice@x.com | 3 |
| SKU-100 (×2) | SKU-100 | 2 |
| unique-row (×1) | not listed | — |
Only lines that appear two or more times are listed. Anything unique is left out, so the report is a focused view of exactly what repeats.
Why it runs in your browser
All comparison happens locally in JavaScript. Your list is never uploaded, which keeps sensitive data — customer emails, internal IDs, private records — on your machine. It is instant, and because ByteTools installs as a PWA it works even offline.
Try the Find Duplicate Lines — free and 100% in your browser.
FAQ
Does it remove the duplicates or just report them?
It reports them, showing each repeated line and its count without altering your input. If you want to delete duplicates, use a dedicated remove-duplicates tool afterward.
How do I count how many times each line repeats?
The count is shown next to every duplicated line automatically, so you can see at a glance whether something appears twice or two hundred times.
Can I ignore capitalization differences?
Yes. Turn on case-insensitive matching and lines differing only in case are grouped together and counted as one value.
Is my list safe to paste?
Yes. Everything runs in your browser and nothing is sent anywhere, so even confidential lists stay private.
Related free tools
- Remove Duplicate Lines — delete the repeats once you have found them.
- Line Counter — count total, non-empty, and unique lines.
- Sort Lines — order a list before or after checking.
- Remove Empty Lines — clean blank rows out of the data.
Built by ByteVancer
ByteTools is a free product of ByteVancer, a software and web development studio building web apps, SaaS, and custom software. Need a private data-auditing tool for your own team? Explore what ByteVancer can build.
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