---
title: "Debug ViewHelper <f:debug>"
manual: "Fluid ViewHelper Reference"
version: "main"
permalink: "https://docs.typo3.org/permalink/t3viewhelper:typo3-fluid-debug@main"
source: "Global/Debug.rst"
modified: "2026-09-15T08:11:10+00:00"
---

# Debug ViewHelper `<f:debug>`

ViewHelper to generate an HTML readable dump of variables or objects. The output can be navigated like a nested tree. The output will be put at the beginning of the HTML response, unless the `inline` attribute is set, so that the output will be placed at the specific place where it is placed inside a Fluid template.

Go to the source code of this ViewHelper: [DebugViewHelper.php (GitHub)](https://github.com/TYPO3/typo3/blob/main/typo3/sysext/fluid/Classes/ViewHelpers/DebugViewHelper.php).

**Arguments**

The following arguments are available for the debug ViewHelper:

-   **ansiColors**

    -   *Type:* bool
    -   *Default:* false

    If TRUE, ANSI color codes is added to the plaintext output, if FALSE (default) the plaintext debug output not colored.

-   **blacklistedClassNames**

    -   *Type:* array

    An array of class names (RegEx) to be filtered. Default is an array of some common class names.

-   **blacklistedPropertyNames**

    -   *Type:* array

    An array of property names and/or array keys (RegEx) to be filtered. Default is an array of some common property names.

-   **inline**

    -   *Type:* bool
    -   *Default:* false

    if TRUE, the dump is rendered at the position of the \<f:debug> tag. If FALSE (default), the dump is displayed at the top of the page.

-   **maxDepth**

    -   *Type:* int
    -   *Default:* 8

    Sets the max recursion depth of the dump (defaults to 8). De- or increase the number according to your needs and memory limit.

-   **plainText**

    -   *Type:* bool
    -   *Default:* false

    If TRUE, the dump is in plain text, if FALSE the debug output is in HTML format.

-   **title**

    -   *Type:* string

    optional custom title for the debug output

## Examples

### Simple

```
<f:debug>{myVariable}</f:debug>

```

\[A HTML dump of myVariable value\]

### All Features

```
<f:debug title="My Title" maxDepth="5"
    blacklistedClassNames="{0:'ACME\BlogExample\Domain\Model\Administrator'}"
    blacklistedPropertyNames="{0:'posts'}"
    plainText="true" ansiColors="false"
    inline="true"
>
    {blogs}
</f:debug>

```

\[A HTML view of the var_dump\]