Remove Duplicate Lines — Unique List Maker
Paste any list (tags, emails, SKUs, paragraphs). Dedupe instantly with options for case sensitivity, keep first/last, and sorting. All processing happens in your browser.
Scope & Limits
- What it does: Treats each line as one item and removes duplicates based on your options.
- What it doesn’t do: Doesn’t parse CSV columns or JSON; for per-column dedupe use a spreadsheet or a column-aware tool.
- Best for: Tags, emails, SKUs, URLs, paragraphs, and quick text cleanup.
- Privacy: 100% browser-side; nothing is uploaded.
How to use this tool
- Paste your list into the left box — one item per line.
- (Optional) Pick options:
- Case-sensitive — treat Apple and apple as different.
- Trim whitespace — clean leading/trailing spaces on each line.
- Ignore empty lines — drop blank lines.
- Keep first / last — which duplicate to keep.
- Sort — keep original order, A→Z, Z→A, or by length.
- Show removed — see all duplicates that were removed.
- Frequency table — see counts for each unique line.
- Click Remove Duplicates (or press Ctrl/Cmd+Enter).
- Copy or download the Unique lines from the right box.
Shortcuts: Ctrl/Cmd+Shift+C copies unique; Esc clears.
Why use this Unique List tool?
Messy lists waste time and cause errors—especially when you’re working with emails, SKUs, tags, or URLs. Our 1-Click Remove Duplicate Lines tool creates a clean, unique list instantly. Choose whether to keep the first or last occurrence, toggle case-insensitive matching, and trim stray spaces so results are consistent for spreadsheets, CMS imports, and code workflows.
Popular, real-world use cases
- Email & CRM: Remove duplicate subscribers before importing to Mailchimp, HubSpot, or Klaviyo.
- SEO & content: Clean URL lists, sitemap exports, and keyword tags.
- Data & dev: De-duplicate IDs, error codes, or package names before committing.
- E-commerce: Merge vendor SKUs, strip repeated attributes, and keep one canonical value.
- Research: Consolidate citation links or survey answers without manual checks.
Pro tips for perfect results
- Normalize spacing: Enable trimming so lines that only differ by trailing spaces are treated as duplicates.
- Case rules: If “ABC” and “abc” should be the same, turn on case-insensitive mode.
- Order matters: Choose “Keep first occurrence” to preserve your original ranking or priority.
- Spot near-duplicates: If lines differ by punctuation or accents, clean with Remove Accents / Diacritics first.
- Sort after dedupe: For tidy outputs or grouping, run Alphabetize / Sort List after duplicates are removed.
Quick examples
Input
apple Apple banana banana BANANA grape
Settings: Trim spaces ✓ Case-insensitive ✓ Keep first occurrence
Output
apple banana grape
Privacy & performance
This tool runs in your browser—your text isn’t uploaded to a server. It’s fast, private, and reliable for long lists. For extremely large files, paste in chunks or use the optional “Download .txt” button to save results safely.
When to combine with other FATAIM tools
For the cleanest lists, consider this sequence:
- Remove Line Breaks / Fix Wrapped Text → remove soft wraps.
- Remove Accents / Diacritics → normalize characters.
- Remove Duplicate Lines → produce a unique list.
- Alphabetize / Sort List → present neatly (A→Z, Z→A, by length, etc.).
Get a clean, unique list—instantly
Paste your data, choose your rules, and click Convert. In one step, you’ll remove duplicates, standardize spacing, and get a ready-to-use unique list you can copy or download for spreadsheets, email tools, and CMS imports.
FAQ
How do I use the Remove Duplicate Lines tool?
Paste your list (one item per line), choose options such as Case-sensitive, Trim whitespace, Ignore empty lines, Keep first/last, and sorting, then click “Remove Duplicates” (or press Ctrl/Cmd+Enter). Copy or download the unique lines; optionally view removed duplicates and a frequency table.
How do “Keep first” vs “Keep last” work?
Keep first preserves the earliest occurrence and drops later ones. Keep last keeps the latest occurrence; we scan from the end and restore original order.
What does “Ignore empty lines” do?
Any blank line (after optional trimming) is discarded. Turn this off if empty lines matter.
Why is my sorted output different?
If you choose A→Z, Z→A, or length, we sort the final unique list using locale-aware comparison. “Keep original order” preserves input order.
What about huge lists?
Processing is streaming-friendly and runs in your browser. For extremely large lists, keep sorting = “Keep original order” for best performance.
Is my data private?
Yes. Everything happens locally in your browser; we don’t send or store your text.
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