How to Check an Email List for Near-Duplicate Addresses (jon.smith vs jon.smyth)

To check an email list for near-duplicates, compare each address with the others and flag pairs that are one edit apart. The near-duplicate email finder does this for a whole column. It looks in the part before the @ and in the domain, and finds one letter changed, two letters swapped, a character added or missing, or one digit changed, then lets you download the pairs.

It runs in your browser. The list is not uploaded.

The by-hand way

1. Sort the list alphabetically so look-alikes sit together.
2. Scan for neighbours such as jon.smith@ and jon.smyth@, or jonh@ and john@.
3. Sort by domain and scan again for domains that differ by a letter.

Sorting catches only the ones that start the same. A typo in the first letter lands far away from its twin.

Step 1: upload the list

Upload a CSV or .xlsx, or paste the cells with the header row first. It needs a column of email addresses.

Step 2: run the check

Press Find similar addresses. Every cell is trimmed and lower-cased, cells that are not shaped like addresses are skipped, and exact duplicates are counted once.

Step 3: read the pairs

Pairs are grouped by how they differ.

Difference	Example	Usually
One letter changed	jon.smith and jon.smyth	The same person typed twice
Two letters swapped	jonh and john	The same person typed twice
One character added or missing	smith and smiith	The same person typed twice
One digit changed	sales1 and sales2	Often different people, listed last

The tool does not choose which of a pair is right. Names shorter than four letters and domains shorter than five characters are not compared, because short strings are one edit from many others.

Which one is right

For a mistyped domain such as gmial.com, the email typo corrector fixes it, and email typo correction explains why typos reach a list. For the rest, a mailbox check shows which of the two addresses accepts mail, and the other can go. To find the same person at different addresses by name, use the duplicate contact finder and read finding duplicate contacts with different emails. Exact copies go first, with remove duplicate emails.

What this check cannot do

• It reads the text only. It cannot say which address of a pair exists.
• Only pairs one edit apart are found.
• Names under four letters and domains under five characters are not compared.
• Digit-only differences are often different people.

Check which address of each pair is real

Download the pairs, remove the wrong address of each, then check what is left. Upload the list on the verify page: the first 100 email checks are free with a Google sign-in, no card. Each address comes back valid, risky or invalid with a reason, and nothing is sent to anyone on the list. For larger or recurring lists, see bulk email verification, list cleaning and pricing.

Check your list now

Open the near-duplicate email finder.