# ContentImageByKey()

Returns an `img` tag in which the `src` attribute is the path to an image from Content Builder. The img tag includes the title and alt information for the selected image, a `border` attribute set to `0`, and a `thid` attribute that contains an ID for the image.

This function only works with Image-type content in Content Builder. It doesn’t work with Image Block content.

## Availability

<table>
  <tr>
    <td>Marketing Cloud Engagement</td>
    <td>✅ Yes</td>
  </tr>
  <tr>
    <td>Marketing Cloud Next</td>
    <td>❌ No</td>
  </tr>
</table>

## Syntax

```
ContentImageByKey(imageExternalKey, defaultImageExternalKey)
```

The `ContentImageByKey()` function has two parameters:

- `imageExternalKey` (string): Required. The external key of an image in Content Builder.
- `defaultImageExternalKey` (string): Required. The external key of a fallback image in Content Builder. The function uses this image if it can’t find the image that you specified in the `imageExternalKey` parameter.

## Usage

To use this function, pass it the external key of an image from Content Builder. You can optionally specify a default image to use if the function is unable to find the first image.

```
%%=ContentImageByKey('CorpLogo','DefaultImage')=%%
```

If the function finds the image that you specified in the first parameter, it returns an `<img>` tag that refers to that image.

```
<img title="Logo" alt="Logo" src="http://images.example.com/logo.gif" border="0" thid="8039b510-bb65-4b3b-a803-b12406122c48">
```

If the function doesn’t find the specified image, it returns an `<img>` tag that refers to the image that you specified in the second parameter.

```
<img title="Default" alt="Default" src="http://images.example.com/default.gif" thid="aadf20eb-b39c-4750-90b8-fc1a46090ef1">
```