RemoveDup.com

Paste text or 📂 Choose File (.txt, .csv, .log). Click ▶ PROCESS to run. ⬇ Download saves the result; 📋 Copy Result copies it. Stats show lines In / Out / Removed.

Replaces all occurrences of a plain-text string in every line. Leave Replace empty to delete matches entirely.

Prepends or appends text to every line after all filters are applied. Useful for SQL IN-clauses, JSON arrays, or quoted lists.

Transforms the case of every line. Options: lowercase, UPPERCASE, Title Case (first letter of each word), Sentence case (first letter of line only).

Keeps only the first occurrence of each exact line. Case-sensitive: Alice ≠ alice. Combine with Case Conversion to deduplicate regardless of case.

Scans each line for an email address and keeps only that address. Lines with no email are dropped. Perfect for cleaning exported contact lists.

Keeps only lines that are themselves a valid email address (must match x@x.x pattern). Removes lines that aren't emails at all.

Strips lines that are blank or contain only whitespace. Run after other filters that may leave gaps.

Flips the list upside-down — last line becomes first. Useful when a log or export is in reverse-chronological order.

Sorts all lines alphabetically (locale-aware, ascending). Combine with Remove Duplicates for a clean sorted unique list.

Orders lines shortest to longest by character count. Useful for spotting outliers or building nicely-indented outputs.

Shuffles lines into a random sequence. Re-click PROCESS for a new shuffle each time.

Removes leading and trailing spaces (and tabs) from each line. Does not affect spaces inside the line.

Keep only lines longer than, shorter than, or equal to a number of characters. Set the condition in the dropdown and the threshold in the number box.

Removes any line whose beginning matches the text or regex you enter. Enable the toggle to activate. Supports regex patterns.

Removes lines whose end matches a text or regex pattern. Toggle to activate.

Acts as a filter — only lines that match your text or regex are kept; everything else is removed. Toggle to activate.

The inverse: lines matching your text or regex are removed; the rest are kept. Toggle to activate.

For each line, extracts the first match of your regex pattern and uses that as the output. Lines with no match are dropped. Powerful for pulling out specific data.