The Scenario
You are a CRM manager. You suspect your Omnisend contact list has thousands of duplicate entries. The list was built over four years through three different import tools, two agencies, and at least one "just paste the CSV" moment that nobody documented.
You need to pull the entire list into a Google Sheet, find the duplicates, clean them, and re-import a deduplicated version. The campaign you are planning next month segments by subscriber status, and duplicates mean subscribers get emails twice.
The bad version of this week:
- You look for an export button in Omnisend's contacts section
- Find one, but it caps the export at 5,000 rows and you have 47,000 contacts
- Export in chunks, get 10 separate files
- Paste them together, get duplicate column headers in rows 5001 and 10001
- Start looking for duplicate emails in a 47,000-row sheet using manual filters
- Realize three days later you have cleaned 8,000 rows and still have 39,000 to go.
The fast version is one prompt and the flagged duplicates are in the sheet before your next meeting.
The Easy Way: One Prompt in SheetXAI
SheetXAI pulls the full Omnisend contact list into the sheet and flags duplicates, handling pagination so you do not have to manually stitch export files together.
Open the SheetXAI sidebar and type:
List all Omnisend contacts and write contact ID, email, first name, last name, subscription status, and creation date into this sheet — flag any email that appears more than once with DUPLICATE in a new column.
SheetXAI pages through the Omnisend contacts endpoint until it has every record, writes them into the sheet, and adds a column marking any email address that appears on more than one row.
What You Get
Your full Omnisend contact list in the sheet, with duplicates flagged:
- Contact ID — so you can reference specific records when re-importing
- Email, first name, last name — the standard contact fields
- Subscription status — so you can see if duplicates have conflicting subscription states
- Creation date — so you can keep the oldest record (or the newest, your choice)
- Duplicate flag column — "DUPLICATE" on every row where the email appears more than once
You decide which duplicate to keep. Ask SheetXAI to keep the most recently created, or the one with the active subscription status, and delete the rest.
What If the Data Is Not Quite Ready
Contact cleanup is never just "find and remove." SheetXAI handles the nuance.
When duplicates have different subscription states
One copy of an email is subscribed, the other is unsubscribed. Keeping the wrong one breaks the campaign.
Find all duplicate emails in this sheet. For each set of duplicates, keep the row with status "subscribed" if one exists, otherwise keep the row with the most recent creation date. Mark all other duplicates as "DELETE" in the flag column.
When you also want to remove contacts with invalid email format
The import flagged some emails but they still made it in. You want to clean those too.
In addition to flagging duplicates, add a second flag column. For any row where the email does not follow standard format (contains @, has a domain with a dot), write "INVALID EMAIL." Then I will filter and handle those separately.
When you want to write the clean list back to Omnisend
After deduplication, you want the cleaned list re-imported without the rows marked for deletion.
After flagging duplicates, filter to rows where the flag column is empty (not marked DUPLICATE or DELETE). Export that clean list as a new Omnisend batch contact import, overwriting existing contact records by contact ID. Write the batch job ID into cell H1.
When you want the full cleanup pipeline in one shot
You want the pull, the flagging, the decision logic, and the re-import all in one instruction.
Pull the full Omnisend contact list into this sheet. Flag duplicates. For each duplicate set, keep the record with "subscribed" status (or most recent creation date if no subscribed record exists). Mark the others DELETE. Also flag any row with invalid email format as INVALID. Then re-import all clean rows (not marked DELETE or INVALID) into Omnisend using the batch API, updating by contact ID. Write the final imported count into cell I1 and the excluded count into I2.
The pattern: pull, audit, decide, re-import — one session, one prompt.
Try It
Get the 7-day free trial of SheetXAI and open a Google Sheet, then ask it to pull and deduplicate your Omnisend contact list. The Omnisend integration is included in every SheetXAI plan. For related workflows, see how to bulk import contacts into Omnisend or the Omnisend in Google Sheets overview.