How to Merge Duplicate Records in Airtable

Duplicate records in Airtable accumulate in predictable ways: a form submitted twice, a CSV import run on data that was already there, a team member creating a contact that someone else had already added with slightly different spelling.

Once duplicates exist, the DeDupe extension is the cleanest native way to handle them. It finds matches, shows the duplicates side by side, and lets you choose which field values to keep, including combining values from both records rather than simply picking one.

Installing the DeDupe Extension

Installing DeDupe extension

  1. Open your Airtable base

  2. Click Tools in the top toolbar, then Extensions

  3. Click + Add an extension and search for DeDupe

  4. Click Add to install it

The DeDupe extension is free. It is available on paid Airtable plans.

Step 1: Choose Your Table and Matching Fields

DeDupe extension showing table and field selection screen

  1. Open the DeDupe extension

  2. Choose the table where you want to find duplicates

  3. Optionally select a view to limit the scan to a subset of records

  4. Select the field or fields to match on - for example, Company Name, Email, or Phone Number. Selecting multiple fields means a record is only flagged as a duplicate if all selected fields match

Then choose a matching type:

  • Exact - case-sensitive, character-for-character match. "Acme Corp" and "acme corp" would not match.

  • Similar - matches records with the same value but different capitalisation, punctuation, or word order. "Acme Corp" and "acme corp" would match.

  • Fuzzy - looks for typos and character transpositions. Use this carefully - it can produce false positives where records are flagged as duplicates when they are genuinely different.

Click Find duplicates to run the scan.

Step 2: Review Duplicate Groups

The extension groups matching records together and shows them side by side. Each group has one record highlighted as the suggested primary record, which is the one that will be kept.

Review each group and confirm or change the primary record. The primary record is the one whose revision history and comments will be preserved after the merge. Non-primary records are deleted.

Step 3: Choose Which Field Values to Keep

For each field, you can:

  • Keep the primary record's value - the non-primary record's value for that field is discarded

  • Keep the non-primary record's value - overwrites the primary record's value

  • Combine values - available for multi-select fields, linked record fields, and attachment fields. Both values are merged into one field. This is useful when each duplicate record has different linked records attached and you want the merged record to have all of them.

Step 4: Merge and Confirm

Click Merge records to finalise the merge. The non-primary record is deleted and the primary record is updated with the values you selected.

Review the merged record to confirm everything looks correct before moving to the next duplicate group.

What Happens to Linked Records on Merge

This is the part most guides skip, and it matters.

When you merge two records, any linked record relationships from the non primary record are transferred to the primary record, as long as you selected “Combine” for the linked record field during the merge.

If you selected "Keep primary" for a linked record field, the linked records from the non-primary record are lost. They are not automatically transferred.

This means if "Acme Corp (duplicate 1)" is linked to three deals and "Acme Corp (duplicate 2)" is linked to two different deals, combining them gives you a merged record with all five deals. Choosing to keep only one version loses the other three or two.

Always review linked record fields carefully during merge and choose "Combine" for any linked record fields where both versions have data you need.

Preventing Duplicates From Coming Back

The DeDupe extension fixes existing duplicates but does not prevent new ones. A few approaches worth combining:

For form submissions: use Fillout to build your forms. Fillout has a built-in duplicate prevention feature that checks whether a matching record already exists before accepting a new submission. Available on Fillout Business and Enterprise plans, currently works on email and single line text fields.

For ongoing detection: set up a scheduled automation that runs the duplicate-flagging approach described in How to Find, Remove, and Prevent Duplicate Records in Airtable. This flags potential duplicates automatically as new records are created so they can be reviewed and merged before they accumulate.

For CSV imports: use the CSV Import extension's merge mode to match incoming rows to existing records by a unique identifier rather than always creating new records. See How to Import Updated Data into Airtable Without Creating Duplicates for how to configure this.