> ## Documentation Index
> Fetch the complete documentation index at: https://www.tella.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Blur or highlight part of the screen

> Hide sensitive details with a blur or draw attention to an important area with a highlight.

<iframe src="https://www.tella.tv/video/vid_cmjkg0hv900e104lhc8u34yh0/embed?b=0&title=0&a=1&loop=0&t=0&muted=0&wt=0" width="100%" style={{ aspectRatio: "16/9", border: "none", borderRadius: "8px" }} allow="autoplay; fullscreen" />

Use blur to hide sensitive information in your recording. Use highlight to mask everything except the area you want viewers to notice. Both are in the **Effect** sidebar with zooms and cursor controls.

## Open blur and highlight controls

1. Open your video in the editor.
2. Click **Effect** in the sidebar, or press `E`.
3. Find **Blur & highlight**.

The Effect timeline shows zooms, blurs, and highlights together, so you can compare and adjust their timing in one place.

## Blur sensitive information

1. Move the playhead to where the blur should start. You can also select a range on the timeline or in the transcript.
2. Click the plus button beside **Blur & highlight**. Tella adds a blur and opens its settings.
3. On the canvas, drag and resize the blur to cover what you want to hide.
4. On the Effect timeline, drag the card or either edge to change its timing.

* Drag the start or end of the blur to change its duration.
* Drag the card left or right to move it earlier or later.
* Hold **Option** on Mac or **Alt** on Windows while dragging to turn snapping off.

<Tip>Hover over a blur or highlight card or either duration handle to preview the exact frame under your pointer. While you drag a duration handle, the preview follows the moving edge while the red playhead stays parked.</Tip>

<Note>A selected time range wins over the playhead. If you select several ranges, Tella adds one effect to each. Clear the selection first when you want the playhead to decide where the effect starts.</Note>

<Note>Blur and highlight timing follows your edited playback timeline, so removed sections are skipped. If the playhead is inside a cut, Tella starts the effect at the first visible frame after that cut.</Note>

## Add a highlight

1. Click the plus button beside **Blur & highlight**.
2. In the selected effect's settings, change **Type** from **Blur** to **Highlight**.
3. Position and resize the clear area around what you want viewers to notice.
4. Adjust its timing on the Effect timeline.

You can also open **Add** in the timeline toolbar and choose **Add highlight** directly.

## Add overlapping effects

Click the plus button again to add another blur, or use **Add** in the timeline toolbar to choose a blur or highlight. Position each effect on the canvas and adjust its timing on the Effect timeline.

You can run multiple blurs and highlights at the same time. Overlapping cards move onto separate tracks automatically so each one stays visible. See [work with the multi-track timeline](/docs/help/editing/multi-track-timeline).

## Edit or remove an effect

Select a blur or highlight on the canvas or Effect timeline to open its settings.

* Use **Type** to switch between Blur and Highlight without recreating the effect.
* Use **Intensity** to set how strong the effect is. For a highlight, it controls how dark the area outside the clear region gets. For a blur, it makes the blur heavier.
* Use **Transition** to choose **Smooth** or **Hard cut**.

<Note>A blur never gets lighter than its default. Lowering **Intensity** on a blur returns it to the standard strength, so whatever it covers stays hidden.</Note>

* Click **Delete** in the timeline toolbar, or right-click the card and choose **Delete blur** or **Delete highlight**.

## Animate a blur or highlight

By default, a blur or highlight uses a **Hard cut**, appearing and disappearing instantly. Select **Smooth** under **Transition** to fade it in and out instead.

<Note>You cannot split a blur or highlight while its transition is set to **Smooth**. Change it to **Hard cut** first if you need to split it.</Note>

## Split at the playhead

1. Select the blur or highlight.
2. Move the playhead inside the effect.
3. Click **Split** in the timeline toolbar, press `X`, or right-click the card and choose **Split at playhead**.

The new right half keeps the same type, position, size, intensity, and transition. You can then resize, reposition, or retime either half independently.

## Use blur and highlight with crops, layouts, and zooms

Blur and highlight work alongside layouts and zooms. You can keep one area highlighted while another stays blurred as a zoom plays.

<Note>Blur and highlight areas follow the **Shape** selected in **Style** for that layout section. In a full layout, the camera or screen frame stays square at the canvas edge, while the effect keeps your **Rounded** or **Circle** shape in the editor and exported video.</Note>

<Tip>When you add a blur or highlight during a zoom, Tella places it in the center of the visible zoomed area. You can then drag and resize it across the full screen recording, including areas outside the canvas.</Tip>

If a crop still includes the full covered area, the effect stays anchored to the same content. If the crop cuts through part of it, Tella adjusts the effect to fit. Resetting the crop keeps that adjusted position and size. If the crop removes the covered area completely, Tella removes the blur or highlight.


## Related topics

- [Overlays overview](/docs/help/editing/overlays.md)
- [Blurs and highlights](/docs/mcp-tools/blurs-and-highlights.md)
- [Work with the multi-track timeline](/docs/help/editing/multi-track-timeline.md)
- [Add zooms and screen effects](/docs/help/editing/add-a-zoom.md)
- [Update a highlight](/docs/api-reference/clips/update-a-highlight.md)