Donaldson R F Remove Duplicate Emails
Paste a list of email addresses (or open a file) and get it back with every duplicate removed — the first copy stays where it was.
How it works
The list is split into addresses (one per line; commas, semicolons and tabs also work), then each address is compared with the ones before it. The first occurrence is kept and later copies are dropped, so your original order is preserved. By default John@Example.com and john@example.com count as the same address, because email domains are not case-sensitive and almost every mailbox is treated that way.
Anything that is not a valid address (a typo, a name) is kept as it is, so nothing is lost silently; the addresses that are not valid are easy to spot in the result. To keep the lists separate, use compare two email lists.
Frequently asked questions
Is my list uploaded anywhere?
No. The list is processed in your browser, in a background worker, and never sent to our server.
How big can the list be?
The limit is shown at the top of the page (currently 10 MB or 500,000 lines). For bigger lists, split them first.
Does it change my addresses?
No. Addresses are only removed, never edited, and the first spelling of each address is the one kept.