Guide to building fillable forms into your app

Guide to building fillable forms into your app

A summarized guide for developers on how to build form solutions inside your applications.

Welcome developers and product teams! So you want to build and support forms inside your application. You’ve come to the right place. This comprehensive guide is tailored for developers eager to build user-friendly fillable forms and document features into their applications. And do it right the first time. In this guide, you will discover practical steps, effort insights, team talent needed, costs, and unexpected requirements to transform your approach to form feature development and support. This guide is your key to crafting intuitive, aesthetic, and scalable form experiences, ensuring your application delivers what your users deserve.

Before we get started

We’ve spent the better part of six years building Joyfill to accommodate digital fillable forms and document feature demands for our own users. We’ve mastered the art of forms by making all the mistakes imaginable. We’ve decided to put this guide together to help product teams save time by avoiding the same mistakes we’ve made. We continue to build the form tooling developers need to accomplish these daunting form developments. We should mention that if you don’t want to build an entire form solution from scratch feel free to check out our form builder SDK to shortcut the process tremendously. With that out of the way, let’s dive into building your fillable form solution!

The fundamental tradeoff

The initial decision to construct your own fillable form solution involves a common tradeoff consideration: What features will your team need to defer while developing and sustaining form functionalities?

If your customer base and core product offerings are already established, a product roadmap is likely in place. Customers expect the features they’re paying for, as well as the anticipation of new and enhanced functionalities. The critical question becomes: Which features are you prepared to postpone to accommodate the introduction of form capabilities?

For many teams, this marks the end of the discussion. While forms are valuable add-on features, they are not the core product and clearly not the main focus of the product team. However, this is a guide about building it yourself, so let’s assume that from here forward you’ve done the tradeoff calculation and it’s definitely time to build it yourself.

What to expect from this guide

This guide to building fillable forms in your application will cover the pieces to build your basic fillable forms version 1.0. Building a more advanced form solution is coming soon and will be covered in Part 2. For the scope of this article, we will start with the foundational architecture followed by basic functionality and UI/UX. It’s a more fundamental implementation. We built our form solution with React and React Native, but this article is specific to those languages. Use whatever stack you are comfortable with. Forms are pretty language-independent.

Step 1: Establish the right team

Who is your designer?

A designer on a fillable forms product team is responsible for creating a positive and effective user experience, translating user needs into visually appealing, and functional designs, and collaborating with other team members to bring the product to life. For example, if the form-building interface looks and feels more difficult than it is and is missing the intuitive flow it can cause disinterest and negative experiences with your product users. The goal is the create an easy and enjoyable experience for your users. The UX/UI is the first step to accomplishing that.

Who are your developers?

The amount of developer resources needed for fillable forms heavily depends on the scope of the project. The level of complexity you want to support, the number of features to offer, and the completion timeline all dictate the level of manpower needed. At Joyfill, we built our fillable form SDKs with a much larger team because we natively support multiple programming languages, but for the scope of this guide, one senior developer should suffice for a basic fillable form version 1 written in your one language. More developer resources will need to be pulled, a mobile developer for example, if you want to support mobile fillable forms, etc.

Who is your project manager?

A project manager is responsible for planning, coordinating, and overseeing the successful execution of the form project. Whether you are building fillable forms from scratch or revamping your existing form solution, it’s their job to handle changes to the project scope and requirements, resolve conflicts, and maintain project integrity. Ultimately, their role is crucial in delivering high-quality form experience on time and within budget, while continuously seeking to ensure the end product is what your users need and expect.

Step 2: Define what you’re actually building

What are you building when you say “forms”. Is it a form builder, PDF filler, external survey, mobile data collection, etc? This guide will focus on internal fillable eforms — enabling users to build, fill out, and store form documents digitally inside your application. For this, you will need a do-it-yourself form builder, filler, and viewer. Secondly, how robust will your form solution be? What features will you offer? Forms is not a new thing and are almost expected by users nowadays. Delve into the depth of your form solution by considering its robustness and the array of features it will offer. Carefully assess the needs of your users and how they will engage with the various features of your form application. This meticulous understanding will guide the development process, ensuring your solution aligns seamlessly with user expectations and requirements.

Unexpected architecture prerequisites

The architecture should be flexible, provide a mechanism for defining document structures, allow for the simultaneous handling of multiple instances of templates and documents, and support effective search and query operations on the stored documents. These features are particularly important in scenarios where there is a need to manage and manipulate a variety of data and document types dynamically.

Below are some of these elements:

Dynamic Data Structure: A dynamic data structure refers to a data organization that can change in size and structure during the execution of a program. This is crucial for accommodating varying amounts of data and adapting to different requirements without requiring significant changes to the underlying system.

Templating Structure: A templating structure implies the use of templates to define the structure or layout of documents or data. Templates act as predefined formats that can be filled with variable data. This is particularly useful for ensuring consistency in the presentation of information.

Support for Independent Instances of Templates and Documents: The architecture needs to support the creation and management of multiple instances of templates and documents concurrently. This allows for the simultaneous processing of different sets of data or the creation of distinct documents based on the same template.

Searching and Querying Documents: The system should provide mechanisms for efficiently searching and querying documents. This involves the ability to find specific information within documents, filter based on criteria, and retrieve relevant data quickly.

The basic features

While achieving basic form capabilities may require incorporating seemingly straightforward features, the complexity often surpasses the initial evaluation. Nonetheless, the following outlines the fundamental features essential for version one. The advantage lies in the fact that even these basic capabilities can cater to a significant portion of your users’ needs, given the widespread use of documents in the digital ecosystem.

Field types — Forms encompass various elements, such as plain text fields, long text fields (for paragraph entries), dropdowns, checkboxes, signatures, image uploaders, date fields, and more. This diverse array enhances the user experience, streamlining the form-filling process, minimizing completion time, preventing typos, regulating data input, and ensuring overall submission consistency.

Multiple-column layout — To enhance the sophistication of your form designs beyond the constraints of a basic top-down checklist, it’s crucial to incorporate support for field widths and multi-column layouts.

Pagination and page management — This allows users to navigate through the form easily, especially when it is lengthy or complex. It enables the breaking down of information into manageable chunks, improving user experience significantly. Additionally, page management allows the creation, deletion, and rearranging of pages within the form, providing flexibility and control over the form’s structure and layout.

Set view/read-only statuses of documents — This allows you to control who can view your forms and files. You can set a form to be read-only, meaning it can be viewed but not edited. This is useful for when you want to share a final version of a form without the risk of unwanted changes. You can also control view statuses, determining who can see your form, which is useful for sharing forms with specific teams or across user accounts.

Data extraction and management — Your forms will be filled by your users or programmatically filled. Once the forms are filled, the data extraction process begins. This involves pulling the data from the form and saving it to a designated location, such as your database (and vice-versa). It allows the use of the collected data for further processing, such as generating analysis, visual reports, driving business decisions, or for record-keeping purposes.

Validation — Form validation is a crucial aspect of data collection. It ensures that the data collected is clean, correct, and useful. This can include requirements such as making certain fields mandatory, setting up conditional logic (if this, then that scenario), setting limits on input values, and more. This process can help to prevent errors during data input, improving the accuracy of the data collected, and enhance the user experience by providing immediate feedback and guidance on how to correctly fill out the form.

Field and font styling — An enhanced piece to modern forms is the ability to customize the look and feel of your form fields to match the company brand and improve user experience. This includes the ability to change font type, size, and color, as well as the ability to style form fields, such as text boxes, drop-down lists, and checkboxes, with different colors, borders, and more. Providing a consistent and visually appealing form can enhance user interaction.

PDF generation — This is a key feature in form or document offering. It allows users to convert their digital forms into PDF format. This is useful for sharing, printing, or saving completed forms in a universally accessible format. It also provides the ability to archive and retrieve forms for future reference, ensuring that data is not lost and can be accessed when needed.

Although this is not all the form feature requests you may receive it’s a great foundation to build from as time goes on. This is a great lead into our next set of advanced form features.

The advanced features

Distinguishing your form support from the standard requires the integration of advanced features. These suggestions are specifically tailored for product teams seeking to navigate complex form scenarios and meet unpredictable demands.

Embracing these advanced form features will undoubtedly propel you to an elevated realm of capabilities within the market. If the following are beyond the scope of your resources for version one, feel free to skip this section or plug in these advanced features using Joyfill to save you time.

PDF to PNG backgrounds — This advanced feature allows users to upload a PDF as a background to their form. This can be useful when you want to digitize a physical form or use an existing form as a template. Once uploaded, the PDF can be overlaid with interactive fields, turning a static form into a dynamic, fillable form.

Specialized fields — Specialized fields, such as charts and graphs, allow users to input and visualize data more interactively. They can help to provide context and clarity to the data collected and can be used to display patterns, trends, and correlations that might not be immediately evident from raw data.

Dynamic fields — Dynamic fields, such as tables and field duplication options, provide flexibility and ease in data entry. Tables allow the structuring of data in a grid format, making it easier to understand and manage. Field duplication, on the other hand, lets users replicate a particular field (or multiple fields) as many times as needed, overcoming traditional static field limitations. These features can significantly enhance the user experience, especially for complex forms requiring input of repetitive or structurally similar data.

Mobile data entry experience — An intuitive and user-friendly interface ensures that users can effortlessly navigate through the form on their mobile devices. Responsive design plays a crucial role, adapting the layout to different screen sizes and orientations. Optimizing for touch interactions, minimizing the need for excessive typing, and incorporating logical flow in the form contribute to an overall good mobile data entry experience.

Offline data entry support — This is designed to provide users with a seamless and reliable experience even when disconnected from the internet. This involves the capability to access, input, and edit data offline, with synchronization occurring once an internet connection is re-established. A well-designed offline data entry support system empowers users to work seamlessly regardless of connectivity constraints, fostering productivity and reliability in various operational environments.

Multi-user data merge and collaboration — Form multi-user data merge and collaboration is designed to facilitate seamless teamwork and data consolidation within a shared form environment. It should allow multiple users to simultaneously access and modify the form records.

PDF field auto-detection — Utilize advanced pattern recognition to automatically identify and extract form fields within a PDF document. This technology eliminates the need for manual field identification, streamlining the process of working with PDF forms.

Integrations — This involves establishing a smooth flow of data between the form and the integrated system. Data entered into the form should be accurately transmitted, stored, or processed within the connected environment. An integration aims to create a cohesive and unified experience, allowing the form to interact with other elements of a digital environment.

Step 3: Build your first version

Project scope, requirements, architecture & data models

By now you should already know what your users need and what features and functionality will be included in version 1.

Functionally, the system should support efficient form creation and submission processes. Non-functional requirements encompass scalability to accommodate a growing user base, optimal performance, and a user-friendly interface. The architecture comprises frontend and backend components, including a database for storing form-related data, an authentication service, and API layers for smooth communication. Key data models involve entities like Document, File, Page, and Fields, with relationships reflecting the connections between users, forms, and submissions.

Design and UX

When integrating document and PDF forms into an application, product teams must prioritize design and user experience (UX) components to ensure a seamless user experience. The success of such solutions hinges on intuitive design, responsive layouts, and ease of use functionality.

An intuitive form solution experience is paramount. Clarity and simplicity should be the guiding principles, with well-labeled fields, setting association across forms, pages, fields, and intuitive navigation through complex settings, including conditional logic, data mapping, and other form-building scenarios. Arrange form elements logically to minimize cognitive load and enhance user comprehension. Responsive design is crucial for cross-device compatibility, allowing users to interact with forms seamlessly on various devices.

By addressing these key design components early on, product teams can create a document and/or PDF form solution that not only streamlines data collection but also elevates user satisfaction within the application.

POC, QA, iterations

Quality assurance (QA) is essential for ensuring the success and reliability of your newly built form solution. Through rigorous testing and bug identification, QA prevents the release of flawed features, minimizing user dissatisfaction and reputational damage. Thorough QA processes also contribute to a positive user experience by addressing usability issues and enhancing form stability and performance of the different form modes, whether in build or fill mode, and compatibility across various devices. Ultimately, QA practices support agile development and continuous improvement, ensuring that each release surpasses the previous one in terms of form functionality, modern standards, and innovation.

The nature of any new feature, especially a full-out form solution, requires extensive rounds of iterations during the QA phase involve a systematic and repetitive process before its final release. When bugs are found, developers then address the bugs, and after each fix, regression testing is performed to prevent the introduction of new issues. This iterative cycle continues until the form solution reaches a stable state. Release candidate testing is conducted to validate the features’ readiness for release, covering performance, security, and user acceptance. The process emphasizes collaboration between QA and development teams, ensuring that identified issues are effectively communicated and resolved. Ultimately, these iterative rounds of testing, bug fixing, and regression testing contribute to the creation of a high-quality and reliable form product, meeting the predefined standards before its final release to end-users.


The project timeline is challenging to pinpoint, which we all know is not acceptable by our project manager. Drawing from our experience at Joyfill, we initially spent 12 months to launch our version 1 form builder. On our second venture, we streamlined our process, completing a 10X form solution in just 7 months. However, timelines vary greatly depending on team size, technical expertise with forms and standards, budget, and other factors. Recognizing this, we’ve packaged our form components into developer-friendly SDKs. This initiative aims to save future developers the time and resources we invested over the past 6 years in refining these features. Trust our experience and opt for the shortcut rather than reinventing the wheel with your form solution.

Version 1 launch

At this point, you should have a good technical compass of what version 1 will take to pull off a successful production launch. But for the sake of this large article, here’s a recap of the project questions you should be able to answer:

  • What it will cost to build an MVP

  • What team members will be involved

  • What type of “form solution” you are building

  • What features and capabilities will be available on day 1

  • Estimated timeline of how long it will take to build


Feedback from users is incredibly important when launching a new feature. It is crucial for identifying issues, understanding user needs, driving continuous improvement, building trust and loyalty, and differentiating from competitors. Therefore, it’s essential for product teams to actively solicit, listen to, and act upon user feedback.

This is just the beginning…

As time goes on you will likely implement the given feedback, build more advanced features (refer back to the Advanced Features section of this article), and make improvements to your form solution. Remember to enjoy the journey of building cool things…after all, isn’t that why we decided to be a superhuman developer 😉.

We hope this article was helpful. We have only scratched the surface of the limitless possibilities. Joyfill is for developers who want a forms SDK backed by a credible company focused on creating the next generation of better form technology for the world. Join us. Let’s build the future together!