Extract an email domain with REGEXEXTRACT

How it works, step by step

1. 01B2 holds an email address such as maria.chen@northwind.io.
2. 02The pattern "@(.+)$" looks for the @ sign, then captures one or more characters (.+) up to the end of the text ($).
3. 03The parentheses form a capture group, so REGEXEXTRACT returns only the captured part, northwind.io, without the @.
4. 04Fill the formula down column C to get a domain for every lead.

The same logic in four tools

=TEXTAFTER(B2,"@")

=REGEXEXTRACT(B2,"@(.+)$")

SELECT email,
       substring(email from '@(.+)$') AS domain
FROM leads;

import pandas as pd

leads["domain"] = leads["email"].str.extract(r"@(.+)$", expand=False)

Mistakes that break it

• !REGEXEXTRACT returns #N/A when there is no match, for example a blank cell or an address missing its @. Wrap it in IFERROR(...,"") to leave those rows empty.
• !Stray spaces and mixed case carry through to the domain. TRIM the email first and LOWER the result so Northwind.io and northwind.io group together.
• !REGEXEXTRACT only accepts text. A number in the cell returns an error, so wrap the cell in TO_TEXT if the column mixes types.
• !The Excel formula uses TEXTAFTER, which needs Microsoft 365 or Excel 2024. Older Excel can use =MID(B2,FIND("@",B2)+1,LEN(B2)).

Common questions

How do I extract the domain from an email in Excel?

In Microsoft 365, use =TEXTAFTER(B2,"@"). In older versions, use =MID(B2,FIND("@",B2)+1,LEN(B2)), which returns everything after the @.

What does the $ mean in a REGEXEXTRACT pattern?

$ anchors the match to the end of the text. In "@(.+)$" it makes the captured part run from just after the @ to the last character.

How do I extract text with regex in pandas?

Use Series.str.extract with a raw string pattern that has one capture group, for example df["email"].str.extract(r"@(.+)$", expand=False). Rows without a match return NaN.