Case handling, whitespace/punctuation control, keep-first or keep-last, sorting, and a full duplicate report — all instant, in your browser.
Every line that appeared more than once, with its occurrence count — highest first.
Saved only on this device (browser local storage) — never uploaded anywhere.
Yes. By default the tool keeps the first occurrence of every unique line and preserves the original order. You can switch to keep the last occurrence, or sort the result A-Z / Z-A instead.
Yes. Switch comparison mode to case-insensitive so lines like "Apple" and "apple" are treated as the same entry.
Yes. Processing runs entirely in your browser and handles thousands of lines quickly; very large files depend on your device's available memory.
You choose: keep all blank lines, remove every blank line, or treat blank lines as duplicates of each other so only one remains.
Optionally. You can trim leading/trailing whitespace before comparing, and separately ignore punctuation or extra internal spaces, so lines that only differ by spacing or punctuation are still caught as duplicates.
Yes. The Duplicate Report lists every repeated line along with how many times it appeared, so you can review before exporting.
Yes. Drag and drop a .txt or .csv file, or click to choose one from your device. The result can be copied or downloaded as a new .txt file.
No. All comparison, deduplication, and sorting happen locally in your browser. Nothing you paste or upload is sent to or stored on our servers.
All tools are free. If they've saved you time, consider supporting us.