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# Edit single cells in the grid and turn on cell editing

> Type one-off corrections into Mammoth's data grid with Edit Cells, turn cell editing on or off for a dataset, and fix messages when it won't enable.
>
> Applies to: Where: View › Describe your transformation › Filter, Label & Replace › Edit Cells, or double-click a cell

**Edit Cells** is for one-off corrections where a rule would be overkill. Open it from **Describe your transformation** > **Filter, Label & Replace**, or double-click a cell. Your edits are saved together as one pipeline task.

![View in Editing the grid mode, with a blue header bar offering Discard changes and Apply changes beside an Edit Cells task](https://mammoth.io/docs/images/20260417_123829_Viewin_Editingthegrid_modewiththeblueheaderbar1.webp)

## Edit cells and save them as a task

1. Choose **Edit Cells** in the Transform menu, or double-click a cell. If cell editing is off for the dataset, a dialog asks you to turn it on first (see below).
2. The View enters **Editing the grid** mode, with a blue bar at the top offering **Discard changes** and **Apply changes**.
3. Double-click a cell and type the new value. Edited cells are highlighted.
4. Check the task card in the Pipeline panel. It lists every edit as Original → New, each with an X to remove that change.
5. Click **Apply changes** (or **Add to Pipeline** in Draft mode) to save all edits as one pipeline task, or **Discard changes** to cancel.

Edit Cells tasks can't be copied or duplicated.

## Turn on cell editing for a dataset

Cell editing is a dataset setting and is off by default. It is meant for datasets under 500K rows.

From the dataset's settings in the Data Library:

1. Open the dataset in the Data Library and go to its settings.
2. Click the **Cell editing** switch (it shows On or Off).
3. Mammoth asks "Turn on cell editing?" and notes that it "Re-runs this dataset's pipelines once, and stays on until every edit task is removed."
4. Click **Turn on**.

From the data editor, double-click a cell, or choose **Edit Cells**. If editing is off, the **Enable Cell Editing** dialog opens. The same dialog opens from **Cell editing** (shown as **Enabled** or **Disabled**) on the dataset settings page that the settings icon at the start of the View tab bar opens. It notes that:

- Enabling cell editing will re-run the pipelines in the dataset.
- It will stay active, and you can disable it only if edit tasks are removed.
- It is recommended for smaller datasets (< 500K rows).

Click **Enable Editing**. While the pipeline re-runs, the blue bar at the top reads "Enabling cell editing while the pipeline re-runs". If it stops, the bar reads "Enabling cell editing did not finish", with a **Try again** button. When it's ready you see "Cell editing is now enabled. Double-click a cell to begin editing."

To turn it off, click the **Cell editing** switch again and confirm **Turn off** (on the dataset settings page, **Disable Editing**). This is "Only possible once no cells have been edited, or every edited cell has been removed." See [Dataset settings and history](https://mammoth.io/docs/learn/organise/dataset-settings/).

## Limits

| Limit | Value |
| --- | --- |
| Recommended dataset size for cell editing | Under 500K rows |

## Troubleshooting cell edits

| Symptom | Cause | Fix |
| --- | --- | --- |
| Double-clicking a cell opens **Enable Cell Editing** | Cell editing is off for the dataset | Click **Enable Editing**, or leave it off and use Label & Insert Values |
| Can't turn cell editing off | Some cells are still edited | Remove every edit (or the Edit Cells tasks), then turn it off |

## Related

- [Label rows, edit cells and fill blanks](https://mammoth.io/docs/learn/clean-and-shape/label-and-insert/): set values by rule instead.
- [Add, split, copy and delete columns](https://mammoth.io/docs/learn/clean-and-shape/manage-columns/): add an empty column to fill.
- [Edit, reorder and copy pipeline tasks](https://mammoth.io/docs/learn/clean-and-shape/manage-tasks/): review or remove an Edit Cells task.

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Source: https://mammoth.io/docs/learn/clean-and-shape/edit-cells.md · Updated: 2026-11-08