# Dedupe

> Part of the NocoDB documentation (Product docs > Extensions). Index of all pages: https://nocodb.com/llms.txt. Any docs page is available as Markdown by adding `.md` to its URL.

URL: https://nocodb.com/docs/product/extensions/dedupe
Last updated: 2026-10-03

The NocoDB Dedupe extension finds and merges duplicate records in a table.

## Overview

<img alt="Dedupe" src={__img0} placeholder="blur" />

The Dedupe extension finds and merges duplicate records in a table. It groups records by one or more fields. You do not have to compare records manually. Dedupe finds groups of records with the same values in the selected fields. A guided interface then helps you review, select and merge them into one primary record.

Use this extension to keep datasets clean where duplicate entries are frequent, for example contacts, leads or inventories.

<Callout type="warning">
  Do not merge records that you must keep. You cannot undo a merge. After a merge, you cannot restore the deleted records.
</Callout>

## Finding Duplicate Records

To find duplicate records:

1. Select the **Table** that you want to scan for duplicates.
2. Optional: select a **View** in that table. This limits the scan to the records in that view.
3. Select one or more **Field(s)** to group records by. To make the criteria more detailed, select more fields from the dropdown.

Dedupe finds groups where **two or more records** have the same values in all the selected fields. It shows the groups for review one at a time.

<img alt="Dedupe Find Duplicates" src={__img1} placeholder="blur" />

## Resolving Duplicate Records

For each duplicate group, review and merge the records:

1. Select **one primary record** to keep.
2. If a record in the group is not a duplicate, **exclude** it. Dedupe does not merge or delete excluded records.
3. Optional: for each field, click a value in a record. Dedupe copies that value into the primary record.
4. When you are satisfied, merge the group.

When the merge is complete:

* The primary record stays, with its original primary key.
* The primary record contains the selected field values.
* Dedupe permanently deletes all duplicate records in the group that you did not exclude.

<img alt="Dedupe Review" src={__img2} placeholder="blur" />
<img alt="Dedupe Review - Field Selection" src={__img3} placeholder="blur" />
<img alt="Dedupe Merge" src={__img4} placeholder="blur" />

## Field Behavior During Merge

Dedupe shows all editable fields, but not the grouping field(s) and system fields (for example `id`, `created_at`, `updated_at`). It shows virtual fields (Formula, Lookup, Rollup) only for reference, because you cannot edit them directly. The primary record always keeps its Record ID. Modified timestamps update automatically.

During a merge, Dedupe uses these rules for field values:

| If you                                   | Then                                                      |
| ---------------------------------------- | --------------------------------------------------------- |
| Select a value from a record for a field | Dedupe copies that value into the primary record.         |
| Select no value for a field              | The existing value of the primary record does not change. |

## Group Review Actions

When you review duplicate groups, you can use these actions:

| Action         | What it does                                                                                               |
| -------------- | ---------------------------------------------------------------------------------------------------------- |
| **Skip group** | Go to the next duplicate group. Makes no changes.                                                          |
| **Reset**      | Clear all selections for the current group (primary record, field selections, exclusions) and start again. |

<img alt="Dedupe Actions" src={__img5} placeholder="blur" />

You can skip a group before you select a primary record. You can reset also after you make selections.

## Supported Field Types

**Supported for duplicate detection**

* Text, LongText, SingleLineText
* Number, Decimal, Currency, Percent, Duration, Rating
* Date, DateTime, Time, Year
* Phone, Email, URL
* SingleSelect, MultiSelect
* Checkbox
* Attachment
* JSON, Geometry
* User
* Links & LinkToAnotherRecord (LTAR): many-to-many, belongs-to-one

**Not supported**

* Links & LinkToAnotherRecord (LTAR): has-many, one-to-one

## Key Notes

* Duplicate detection supports **single-field or multi-field grouping**.
* If you select more than one field, records must match on **all** selected fields to be in a duplicate group.
* Each group must have at least **two matching records**.
* Undo / Redo is not supported.
* You cannot restore deleted records.

Dedupe gives you a controlled and efficient way to remove duplicate data. You see and control all records that it merges and removes.

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## Related pages

- [Data Exporter](https://nocodb.com/docs/product/extensions/data-exporter.md): The NocoDB Data Exporter extension exports data from your tables in different formats.
- [Upload Data from CSV](https://nocodb.com/docs/product/extensions/upload-data-from-csv.md): The NocoDB Upload Data from CSV extension imports data from CSV files into existing tables.
- [URL Preview](https://nocodb.com/docs/product/extensions/url-preview.md): The NocoDB URL Preview extension shows a preview of URL content in NocoDB.
- [World Clock](https://nocodb.com/docs/product/extensions/world-clock.md): The NocoDB World Clock extension shows clocks for different time zones in NocoDB.
- [Bulk Update](https://nocodb.com/docs/product/extensions/bulk-update.md): The NocoDB Bulk Update extension updates many records in a table at one time.
- [Page Designer](https://nocodb.com/docs/product/extensions/page-designer.md): The NocoDB Page Designer extension makes printable and shareable layouts from your database records.