# Custom Previewer Tab

### 1. What's it?

You can customize the Custom Previewer Tabs, which always render one format at once time.

This handy tool might help you to fix the following issues:

* Format the BODY as **JSON**, but the Content-Type isn't `application/json`
* Format the body as **Protobuf**, but the Content-Type isn't `application/x-protobuf`
* Render HTML Page on the Web View
* **Beautify** the minified files (HTML, CSS, JS)
* Multipart/form-data
* Try to format the body as the selected type regardless of the `Content-Type`
* Convert MessagePack (msgpack) to JSON
* [Code Generator](/~/revisions/CTFzuwrlmsieJaiDVRDD/advanced-features/code-generator.md) to Swift, Node, Javascript, cURL, ...
* GraphQL Query Prettier

![](/files/-Mi5NXFRNN27yTy40xCF)

{% hint style="info" %}
The selected custom tabs will append to the right side of the Request or Response view 
{% endhint %}

![](/files/-MCAI7C-ERUSwZso1RQz)

### 2. How to use it?

You can either access the Custom Previewer Window:

* Click on the "+" button on the Request/Response bar
* Tools Menu -> Custom Previewer Tab...

### 3. Examples

#### Force render JSON TreeView

Proxyman supports JSON Tree View for better visualization

![](/files/-MNNUbxHWsWRMr_boEpI)

We can show/hide a certain column by Right-Click on the Column Header

![](/files/-MNNUzgYXIXmb4RYSGpL)

#### Force render HTML Page

![](/files/-MCAKf7af-qiy4s1Q-Eb)

#### Beautify the Javascript files

![](/files/-MCAKqYypND8C0vo8X5N)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.proxyman.com/~/revisions/CTFzuwrlmsieJaiDVRDD/basic-features/custom-previewer-tab.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.