Your list (one record per line)
Cleaned & deduplicated
Paste a list above to clean and deduplicate it.
A paste-and-clean tool for address books, membership rosters, mailing lists and attendee lists. Copy your list one record per line and it cleans each row — converting full-width digits and letters to half-width, unifying the various dashes (‐ ― − － etc.) into a plain hyphen, and trimming and collapsing extra spaces — before removing duplicate rows. With the loose-match option on, rows that differ only by spacing or letter case (such as "Yamada Taro" vs "YAMADA TARO") are treated as the same and merged. It shows input, removed and output counts at the top, and lets you copy the result or download it as a .txt file. Each option is an individual checkbox and your settings are remembered in the browser (the list contents themselves are never saved as a setting). Because names and addresses are personal data, all processing happens locally on your device and nothing is ever sent to a server — ideal for normalizing address formatting (aligning the hyphens in street numbers) and checking for double entries.
How to use
- Paste your address book or name list — one record per line — into the input box.
- Toggle the options (full-width → half-width, unify hyphens, tidy spaces…) as needed.
- Copy the cleaned, deduplicated result or download it as a .txt file.
FAQ
Is my list or address data uploaded to a server?
No. Both the cleanup and the deduplication happen entirely in your browser, on your device. Nothing is ever sent to a server, and because it is personal data the list contents are never saved as a setting.
Can it treat "Yamada Taro" and "YAMADA TARO" as the same duplicate?
Yes. Turn on "Ignore spaces & case when matching duplicates" and rows that differ only by spacing or letter case are treated as identical and merged. With it off, only rows that match exactly are removed.
Does it remove duplicates that are far apart in the list?
Yes. It removes duplicates across the whole list, not just consecutive ones, keeping the first occurrence and preserving the original order.
Are Japanese kana and kanji in names converted?
No. Half-width conversion only affects full-width digits, letters, symbols and the full-width space. Kana, hiragana and kanji in names are kept as-is.
What does the "drop blank lines" option do?
It removes empty rows from the output. Turn it off if you want to keep blank separator lines between groups of records.