- Email address
- A shared external/contact ID if you intentionally synchronized one
- Phone only when the formatting is consistent in both files
CRM + email list workflow
Merge HubSpot Contacts with Mailchimp Contacts
Compare two contact exports without VLOOKUP formulas. This workflow is useful for finding contacts present in HubSpot but missing from Mailchimp, contacts present only in Mailchimp, or rows that need CRM fields added.
🔒 Local processing for normal jobsNo signup
Recommended setup
Keep Everything is best when your goal is list comparison because rows missing from either side remain visible.
Extra-space normalization can catch accidental whitespace. Leave Ignore all spaces off unless you deliberately want aggressive matching.
How to merge the lists
- Export the HubSpot and Mailchimp contact files you want to compare.
- Add both files, choose the correct data sheets, and confirm the real header rows.
- Choose Keep Everything and select Email in each file, or use a stronger shared contact ID when you have one.
- Review the live match count, duplicates and output columns before downloading the result.
Contacts can use alternate email addresses in different systems. A true non-match is sometimes a real data difference rather than a formatting problem.
Common list-matching problems
The same person may use a work email in one system and a personal email in the other.
Repeated emails should be reviewed before you assume the relationship is one-to-one.
Country codes and punctuation may need cleaning before phone can be used as a reliable key.
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Normal spreadsheet jobs stay local.
MergeStudio processes normal Excel and CSV jobs in your browser and does not upload those spreadsheet contents to a MergeStudio backend.
Compare the two contact lists
See what overlaps, what is missing and which fields you want in the final workbook.
Open MergeStudio →Product names belong to their owners. MergeStudio is not affiliated with HubSpot or Mailchimp. Export layouts can change; confirm your own fields before merging.