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

# Conditional form integration logic

> Perform an integration only when a certain condition is met. Use conditional logic to create dynamic Fillout forms based on respondents' input.

## What is conditional logic?

**Conditional logic** allows you to make forms that adapt to a respondent's answers. Fillout lets you `Set conditional logic` based on:

* <Icon icon="file-lines" iconType="solid" /> - [previous form inputs](/answer-piping)
* <Icon icon="link" iconType="solid" /> - [URL parameters](/url-parameters)
* <Icon icon="calculator" iconType="solid" /> - [calculations](https://www.fillout.com/help/calculations#pre-fill-fields-with-a-calculation)
* <Icon icon="calendar" iconType="solid" /> - [custom dates](/pre-fill-dates)
* <Icon icon="user" iconType="solid" /> - [enriched emails](https://www.fillout.com/help/lead-enrichment#how-to-enrich-emails) with company information
* <Icon icon="graduation-cap" iconType="solid" /> - [quiz scores](https://www.fillout.com/help/make-a-free-quiz#advanced-quiz-features)

## How to specify a condition

<Steps>
  <Step title="Open the integration">
    Head to `Integrate` and click your **existing** **connection** or connect to a new tool.

    <img src="https://mintcdn.com/fillout-005a867b/eyFDt8-J2lN7LjRZ/images/logic/image-1.png?fit=max&auto=format&n=eyFDt8-J2lN7LjRZ&q=85&s=1033c8ac8b7becad56c04d407d40118a" alt="Screenshot of the Integrate tab of a form" width="2465" height="1442" data-path="images/logic/image-1.png" />
  </Step>

  <Step title="Set a condition">
    At the bottom, click <Icon icon="code-pull-request" />.

    <img src="https://mintcdn.com/fillout-005a867b/eyFDt8-J2lN7LjRZ/images/logic/image-2.png?fit=max&auto=format&n=eyFDt8-J2lN7LjRZ&q=85&s=90f55b4d981c5ceeb579f141339f9521" alt="Screenshot of the Integrate tab of a form" style={{ width:"90%" }} width="1749" height="360" data-path="images/logic/image-2.png" />

    In this example, we'll only add contacts to our [Klaviyo](/klaviyo) newsletter if they will attend the movie screening. Click `+ Add condition`. Choose the field or question on the left followed by the relevant option on the right.

    <img src="https://mintcdn.com/fillout-005a867b/eyFDt8-J2lN7LjRZ/images/logic/image-3.png?fit=max&auto=format&n=eyFDt8-J2lN7LjRZ&q=85&s=1ac97fd910e8a01e660997d1c701f2dc" alt="Screenshot of the Integrate tab of a form" style={{ width:"73%" }} width="1348" height="340" data-path="images/logic/image-3.png" />

    That's it! Now, newsletters will only be sent to those who will attend the screening. Note that you can do this for any integration type, like [Airtable](/airtable), [HubSpot](/hubspot) and [many more](/integrations).
  </Step>

  <Step title="Publish and share">
    Remember to `Publish` your form to make the latest changes reflect.
  </Step>
</Steps>

## Related articles

<CardGroup cols={3}>
  <Card color="#FFC738" icon="eye-slash" iconType="regular" href="/conditional-hiding" title="Hide fields">
    Hide or show fields based on answers, URL parameters or data.
  </Card>

  <Card color="#FFC738" icon="calculator-simple" iconType="regular" href="/calculations" title="Calculations">
    Calculate prices for order forms, compute quiz scores, and more.
  </Card>

  <Card color="#FFC738" icon="table-tree" iconType="regular" href="/condition-logic-groups" title="Condition groups">
    Show or hide fields based on multiple conditions at once.
  </Card>
</CardGroup>