Remove duplicate lines or paragraphs. Exact, trimmed, or case-insensitive matching.
Free Markdown Duplicate Line Remover scans your document for repeated lines and removes them in one pass. Choose exact, trimmed, or case-insensitive matching. Toggle paragraph-level mode to deduplicate entire blocks separated by blank lines instead of individual lines.
Privacy: This tool runs entirely in your browser. Your text is never uploaded, logged, or cached. Close the tab and it's gone. Verify in DevTools → Network: zero requests fire.
Cleaning duplicates from meeting notes or pasted logs shouldn't require a paid editor plugin. The tool runs entirely in your browser.
| Input | Output | Typical size | Speed | Login needed |
|---|---|---|---|---|
| Markdown (.md) | Deduplicated Markdown | Any document size | < 10 ms | No |
Here's what this free tool does in detail — every feature is built to solve real problems, runs entirely in your browser, and is free forever.
Exact mode catches byte-identical lines. Trim mode ignores leading and trailing whitespace, catching lines that differ only by indentation. Case-insensitive mode folds casing on top of trimming, so TODO and todo count as the same line.
For more aggressive formatting cleanup, try the Markdown Formatter.
Enable paragraph-level mode to compare entire blocks separated by double newlines. A repeated paragraph (even if it spans multiple lines) is removed as a whole, while its individual lines stay untouched inside unique paragraphs.
Lines inside fenced code blocks (``` or ~~~) are never removed, even if they repeat. Identical code lines (like repeated import statements in different blocks) are safe.
Need to clean up code formatting separately? Check the Whitespace Normalizer.
By default the first occurrence of each line is kept and later duplicates are removed. Uncheck Keep first occurrence to reverse the behavior and keep the last copy instead, which is useful when later edits are more up-to-date.
Paste any Markdown document into the input, or click Load example to try a built-in sample.
Choose exact, trim, or case-insensitive. Enable paragraph-level for block dedup.
Click Copy cleaned Markdown and paste back into your editor.
Paste the merged file, remove duplicated lines from conflicting edits in one click.
When multiple drafts get combined, duplicated paragraphs are removed instantly.
Server logs often repeat lines. Deduplicate before converting to a Markdown report.
Merge notes from several lecture files and strip the repeated bullet points.
Action items often get pasted twice from chat. One pass cleans them up.
Yes. Free forever, no account required.
Exact (byte-identical), trim (ignore leading/trailing spaces), and case-insensitive (fold casing).
No. Blank lines are structural in Markdown and are always kept.
It groups lines into paragraphs (separated by blank lines) and removes duplicate blocks.
No. Fenced code block contents are never touched.
No. Runs 100% in your browser.