---
title: "Form Preview Function"
slug: "form-builder-form-preview-function"
updated: 2026-10-28T14:24:12Z
published: 2026-10-28T14:24:12Z
canonical: "help.quickbase.com/form-builder-form-preview-function"
---

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

# Form Preview Function

The form preview shows how your form looks to users while you build it, without publishing. This article covers the preview modes in the Form Builder and how to test the form on your own device.

## How the form preview works

The preview sits in the right side bar of the Form Builder. It updates as you build, so you see each change right away, even before you save.

The preview has 3 modes:

| Mode | What it shows |
| --- | --- |
| Web App | The form as it looks in the web app on a computer |
| Mobile | The form as it looks on a phone |
| Preview on my device | A QR code that opens the form in the FastField mobile app on your phone or tablet |

The desktop and mobile modes are a visual preview only. To test how the form works, including rules and calculations, use Preview on my device.

## Preview the form

1. In the Form Builder, select **Preview** in the right side bar.
2. Select the desktop or mobile icon at the top of the preview.

![](https://cdn.document360.io/dd260e4e-10bb-4b66-8fb3-5504c272b904/Images/Documentation/preview-01-mobile.png?sv=2026-02-06&spr=https&st=2026-10-30T03%3A49%3A06Z&se=2026-10-30T04%3A49%3A06Z&sr=c&sp=r&sig=7Zhzyx5CxwOtRDV7DkBdNuH7qxnsI3bb88LtgvDzzDQ%3D)

*The Preview tab in the right side bar showing the form in mobile mode*

When you select a field on the canvas, the preview moves to that field.

![](https://cdn.document360.io/dd260e4e-10bb-4b66-8fb3-5504c272b904/Images/Documentation/preview-02-desktop.png?sv=2026-02-06&spr=https&st=2026-10-30T03%3A49%3A06Z&se=2026-10-30T04%3A49%3A06Z&sr=c&sp=r&sig=7Zhzyx5CxwOtRDV7DkBdNuH7qxnsI3bb88LtgvDzzDQ%3D)

*The Preview tab in web app mode*

> [!NOTE]
> Tip
> 
> To give the canvas more room, select **Preview** again to close the right side bar.

## Test the form on your device

1. Select **Save Draft** to save your latest changes.
2. In the Preview tab, select the **Preview on my device** icon.
3. Scan the QR code with your phone or tablet.

The form opens in the FastField mobile app. You can fill it out and check that rules, calculations, and required fields work.

## Who can use the preview

The preview is part of the Form Builder, so only users who can add or edit forms can use it. Users don't see your draft until you select **Publish**.

## What's next

- [Form status introduction](/fastfield/docs/en/form-builder-form-status)
- [How to use the Form Builder](/fastfield/docs/en/form-builder-how-to-use-the-form-builder)
- [Publish web forms and generate QR codes](/fastfield/docs/en/form-builder-publish-web-forms-and-generate-qr-codes)