Best form builders with conditional logic for 2024

January 24, 2024

How to create personalized dynamic forms

Ever encounter an online form resembling a printed PDF where you had to click through a slew of irrelevant questions in addition to the ones you actually needed to answer? Impersonal and time-wasting, these forms are missing conditional logic, the key element of an efficient and engaging form experience. With conditional logic forms become truly dynamic, adapting to user inputs and external data. They reveal questions and information relevant to the user and hide others, making data collection easier and more effective.

In this article, we’ll discuss the use of conditional logic in forms and explore the top three form builders with conditional logic. We’ll also break down the ways you can leverage it and explain step-by-step how you can implement it in your forms.

Create your dynamic form

The power of form builders with advanced logic

Logic refers to the set of rules that determines the overall structure and sequencing of questions and actions in a form. It’s the backbone of dynamic online forms that progress through a series of questions and can be submitted. You can use special types of logic like dynamic content to engage users and validation rules to ensure you’re getting valid data.

Better user experience (personalized responder journeys) 

Conditional logic lays the foundation for personalized user experiences within forms. Tailor the journey based on individual responses and provide a dynamic and user-centric interaction that fosters engagement. Users feel more connected to the form when the questions they encounter are directly relevant to their preferences and needs. This helps increase completion rates. 

Streamlined processes

When you only show relevant questions based on user input, you not only save time for users but also ensure the collection of accurate and pertinent data, optimizing the overall effectiveness of your forms. 

What can you do with conditional logic?

Conditional logic refers to the specific logic rules that dictate the flow of the form based on user inputs or external data. It’s the key to transforming static forms into dynamic, user-centric experiences that efficiently collect data. There are many ways you can leverage conditional logic to elevate your forms, including:

Qualify leads

Set specific criteria to ensure that you’re getting the right leads. Qualifying factors might include legal requirements–like your state of licensure or minimum customer age. Pregnancy, heart disease and diabetes are all critical health conditions that can help identify someone as an ideal potential patient–or disqualify them. Your mortgage alternative solution might only be available in certain neighborhoods so you can filter by property zip codes.

Koalafi, a fintech startup, has two marketing teams: one for their B2C clients and one for their B2B clients. To address the issue of responders filling out the wrong form, they created one form that uses conditional logic to redirect responders to the correct team. They can now use the time their teams have saved in manually evaluating forms to better serve qualified clients.

Tailored questions to personalize the journey 

When you have relevant information about a patient, the better you can treat them. Does that mean you throw them the kitchen sink of onboarding forms with detailed questions about every aspect of their health? Of course not. Create question branches with more specific questions related to symptoms, health history, medications, etc. that will only appear if responders provide certain answers to questions. Pregnant patients might answer a set of pertinent questions to help customize care. Or responders in different age groups might be routed to tailored question sets. 

Origin, a virtual pelvic floor therapy center, optimizes their form experience with conditional logic. For example, if a responder indicates they have bladder issues, they answer several follow-up questions. If not, they skip to the next section. This creates an informative, yet streamlined onboarding process.

Ask for clarifying questions

Conditional logic is also helpful in addressing customer feedback or dissatisfaction. For instance, if a user submits a low Net Promoter Score (NPS), the form can dynamically trigger follow-up questions to pinpoint specific issues. This helps you gain a deeper understanding of user concerns and allows for prompt resolution.

Redirect in the end of the flow to different websites based on logic

Guide responders seamlessly through their journey and direct them to distinct destinations based on their responses. Whether it's suggesting relevant resources, redirecting to specialized websites, or providing tailored content, conditional logic enables you to create a fluid transition at the end of the form.

The top 3 form builders for personalized forms

When it comes to building dynamic and user-friendly online forms, the choice of a form builder is important. Let's take a closer look at the features and capabilities of three top form builders – Jotform, Typeform and Formsort – to help you make an informed decision.


Jotform is a practical online form builder designed for users seeking a straightforward and functional approach to form creation. You can create simple, efficient forms on its drag-and-drop interface. The platform offers a diverse range of form templates for various purposes, including registrations, surveys, and quizzes.

Jotform supports basic conditional logic, allowing you to dynamically show or hide fields based on responses (if-then scenarios), calculate fields, set requirements, skip to or hide pages, and customize thank-you pages and email recipients.


Typeform allows users to create and design interactive forms, surveys, quizzes, and other data collection tools online. By creating engaging and conversational forms, users can generate leads, register events, and collect customer feedback. The platform is used for a variety of purposes. Typeform aims to provide an interactive and dynamic user experience for building online forms through its conditional logic and integration options.


Formsort is a form builder that stands out for its versatility and functionality. It offers a spectrum of features, from basic logic for personalized responder journeys to more advanced capabilities, including complex calculations and real-time data validation.

You can leverage Formsort’s conditional logic to create a dynamic and streamlined form experience. Functions that hinge on this feature include:

1. Show or hide questions

This can apply to any type of question. For example, if a user selects "Other" as an answer, logic can be applied to dynamically reveal an input field, prompting them to specify further details. This ensures that the form adapts to unique responses, capturing a broader range of information, while keeping the form streamlined when additional fields aren’t necessary.

2. Display select answer choices

In a select question with various choices, you can use logic to conditionally display specific choices based on logic. For instance, if a user indicates a preference for online shopping, the form can dynamically show additional choices related to online retailers.

Formsort - conditional logic in select choices

3. Conditionally render steps (form pages)

Logic applied at the step level allows you to show or hide an entire set of questions on a page of the form based on predetermined conditions. This is particularly useful when a set of questions shares the same logic criteria and needs to be displayed or concealed collectively, streamlining the user journey.

4. Reveal only relevant groups of questions

At the group level, logic can be employed to show or hide an entire section of steps. For instance, a group of questions specifically relevant to females can be conditionally displayed only if the user indicates their gender as female. This ensures a personalized and targeted approach to form interaction.

5. Redirect responders to different links

Redirect logic enables the seamless transition of users to different destinations based on their responses. For instance, after completing a survey, users who express interest in a specific product can be redirected to a tailored landing page. Patients who complete the introductory form can be redirected to follow-up forms tailored more specifically to their health concerns.

How to use conditional logic in Formsort

In Formsort, the logic sits in the question, step or group you want to show conditionally. So for instance, if you inquire about a patient's health conditions and ask them to indicate if they have asthma, the follow-up question about their current asthma medications can be set to display only if the previous answer was "asthma." This contrasts with other form builders, where logic is set at the preceding question, determining the subsequent question based on the selected answer.

Types of logic in Formsort

There are four types of logic available to you in the Formsort studio: simple logic, advanced logic, calculated variables and API variables:

1. Simple logic

A fundamental building block, Simple logic in Formsort allows you to create conditional relationships between questions, steps, or groups. This type of logic is intuitive and ideal for straightforward conditional requirements. Once you create a step, for example, go to Logic and toggle the “Show conditionally” on. On the pop-up, define the condition by selecting the answer for a particular question that triggers the conditional display of the step.

Formsort form builder basic logic

Waybetter, a weight loss program, asks responders if they have an important event ahead that’s helping motivate their weight loss goals. If they have a wedding coming up, for example, they’ll see a question asking for the wedding date.

2. Advanced logic

In cases where your logic depends on a combination of answers, you can use advanced logic. From Logic > Show conditionally, select Advanced. Set up a boolean expression to precisely define the conditions that trigger a specific question, step or group based on a combination of multiple answers. 

Formsort form builder - advanced logic

3. Calculated variables

If you find that you’re adding many conditions in the simple logic editor, you might be beyond the scope of simple logic and may want to check out the calculated variables. This logic lets you calculate quiz results, BMI, and product recommendations. For example, you can use a patient’s height and weight to determine their BMI and add conditional logic that uses the BMI to determine if they qualify or disqualify for your weight loss program. 

First, set up the height and weight questions, setting the input type to “number.” This lets users enter a number or use the up/down arrows to select a numeric value. Separate the height step into feet and inches questions. In the step’s settings, set the minimum and maximum values for each of the fields. You can display the unit of measurement by adding it as a suffix.

Once the height and weight questions are set up, go to Variables > Calculated inline and click +Add calculated variable.

In the menu that pops up, give the variable a name, eg. “bmi,” and switch on “Uses other variables.” This will let you capture the values entered for height and weight. Click +Add variable and add the feet, inches, and weight variables from the list of variables in the dropdown–these correspond to the variables in your questions. 

In the code editor, add the function like this:

function myFunction(height_ft: number, height_in: number, weight_lbs: number): number { // readonly line

//convert height to meters

const heightMeters = ((height_ft)*12 + (height_in)) * 0.0254

// calculate and round

const bmi = Math.round((weight_lbs) * 0.45359237 / (heightMeters ** 2) * 10) / 10

return bmi


You can use the BMI calculated variable in a condition to qualify/disqualify users based on a preset range. 

BMI qualification - Formsort form builder

4. Api variables

Conditional logic combined with API calls can dynamically render questions based on the data retrieved. You can use API variables to fetch real-time data like product prices, store locations in a city, user account data, patient records, currency exchange rates, and much more. After an API call returns the necessary information, you can use the response to create logic on the steps you want to conditionally render. 

Let’s look at an example that identifies a form responder’s current timezone using World Time API and determines which questions to hide based on that information. There are two main parts of this: making the API call and rendering the step conditionally.

Make the API call

First, you can create a select question asking for the user’s city.

In Settings > Variable, set the variable name, eg.user_city.

Formsort form builder - API variables

Next, create an API variable that uses this response to return the time zone. Go to Variables > API lookups and click “+Add api lookup.”

Set a variable name, e.g. user_time_zone, and the variable type, which is the type of data you’re expecting from the API call. In this case, the variable type is a JSON string.

Add the URL you’ll be fetching the data from. Then click on “Variables…” and copy the question variable (user_city). Add it to the URL path to dynamically make the API call. Test the API variable by clicking “Send test request.”

Formsort api variable - form builder

 You want the value of the abbreviation field from the API call. To do that, click “JSON Accessor” in “Result processing.” Type “abbreviation.” At the bottom of the screen, select a city and test the API variable by clicking “Send test request.” Success!

Show a step conditionally

Next, create logic on a question you want to show conditionally and select the API variable you just created. Go to Logic > Show conditionally > Add condition. We’re going to ask this question only if the time zone is EST. Otherwise, it’ll skip to the next question. Try the live preview!

Formsort show API variable conditionally

Elevate your forms with Formsort's dynamic capabilities

The power of conditional logic in forms goes beyond data collection. From tailoring questions based on individual responses to setting up complex conditional scenarios, you can use to Formsort craft dynamic, personalized user journeys. Streamline your onboarding process and enhance your data accuracy with Formsort's intuitive logic features. Leverage the capabilities of Formsort to elevate your forms. Ready to unlock the full potential of conditional logic? Start building with Formsort today and transform the way you engage with your audience.