---
title: Fill empty cells
description: Fill null or empty cells in selected columns using previous, next, mean, median, or mode values.
category: Data Transformation
tags: [fill, empty cells, missing values, data transformation]
---

# Fill empty cells

## **Description**

The **Fill empty cells** activity fills missing values in selected columns using a configured fill strategy. Each column can use its own fill type, allowing a workflow to combine statistical fills for numeric fields with previous or next value fills for ordered data.

### **Supported Features**

- **Multiple columns**: Configure one or more columns in a single activity.
- **Per-column fill strategy**: Choose a different fill type for each column.
- **Previous value fill**: Fill from the previous row using `PreviousValue`.
- **Next value fill**: Fill from the next row using `NextValue`.
- **Statistical fills**: Fill using `Mean`, `Median`, or `Mode`.
- **In-place replacement**: Filled values replace the original column values.

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## **Input**

| Type | Required | Description |
| --- | --- | --- |
| Data | Yes | Input rows containing columns with null or empty values. |

### **Input Scenarios**

#### **1. Numeric Columns**

Use `Mean`, `Median`, or `Mode` to fill missing numeric values.

#### **2. Ordered Data**

Use `PreviousValue` or `NextValue` when row order is meaningful, such as daily readings or grouped records.

#### **3. Mixed Strategies**

Configure different fill types for different columns.

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## **Output**

| Field | Type | Description |
| --- | --- | --- |
| Data | Array | Transformed rows with selected columns filled. Columns not included in `ColumnMap` are unchanged. |

### **Example Output**

| Id | Age | Salary | Department |
| --- | --- | --- | --- |
| 1 | 25 | 50000 | Sales |
| 2 | 28 | 52000 | Sales |
| 3 | 30 | 52333.33 | Finance |

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## **Configuration Fields**

| Field Name | Type | Required | Description |
| --- | --- | --- | --- |
| Column Map | Object Array | No | List of columns to fill and the fill type to use for each column. |
| Column | Previous Data Column | Yes, per mapping | Column whose empty values should be filled. |
| FillType | Dropdown | Yes, per mapping | Fill strategy. Options: `PreviousValue`, `NextValue`, `Mean`, `Median`, `Mode`. |

### **Conditional Field Rendering Rules**

No conditional configuration fields are defined for this activity.

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## **Sample Input**

| Id | Age | Salary | Department |
| --- | --- | --- | --- |
| 1 | 25 | 50000 | Sales |
| 2 |  | 52000 |  |
| 3 | 30 |  | Finance |
| 4 |  | 55000 |  |

---

## **Sample Configuration**

| Column | FillType |
| --- | --- |
| `Age` | `Mean` |
| `Salary` | `Mean` |
| `Department` | `PreviousValue` |

---

## **Sample Output**

| Id | Age | Salary | Department |
| --- | --- | --- | --- |
| 1 | 25 | 50000 | Sales |
| 2 | 27.5 | 52000 | Sales |
| 3 | 30 | 52333.33 | Finance |
| 4 | 27.5 | 55000 | Finance |