Symptom Checker 3—what’s new?

Photo of Aleksandra JędruchPhoto of Łukasz PrzywartyMultiple authors
September 9, 2021
... min read

We've introduced a new version of our Symptom Checker, boasting significant improvements to ensure the best healthcare for people worldwide. With 9 months of work, 25 sprints, 1,000+ tasks, 580+ regression tests, and 12 people involved, here we are, presenting Symptom Checker 3—our most advanced piece of software to date.

At a glance:

The tool may look familiar, but it's an entirely new app! The updated version brings new technology, refreshed design, better performance, enhanced accessibility, and more. Without further ado, let's dive into what has changed and the benefits our customers and users will see.

Our medical Symptom Checker has been updated. Illustration by Aga Więckowska.


The first change may surprise you—we’ve rebuilt the front-end of Symptom Checker entirely from scratch. It's especially important because the front-end is a part of code that users actually see and interact with. The reason for this change was simple—we wanted to provide our customers with better app performance and more frequent product updates.

Plus—good news for the impatient patients (pun intended)—the app now loads faster on both mobile and desktop. This is because it downloads less data and uses less processing power, which is especially important for mobile devices. This fact is confirmed by our Lighthouse Performance score, which is currently 95 out of 100!

Design system

Symptom Checker is now built from small, reusable blocks called components, which help achieve better scalability. There are 200+ different components, both simple (like buttons and input), and more complex (like date picker and mega menu). Each component is tested before it can be used in the application. These components make Symptom Checker’s configuration more effortless than ever.

Symptom Checker's components.


Analytics has become safer because Symptom Checker is now independent of third-party analytics tools such as Google Analytics and Amplitude. We track certain events (i.e., the interaction between the user and Symptom Checker, not personal data) to improve the user experience. Every event we track is now stored in the internal database. And to make this data more readable, all the events are cleared up, grouped, and visualized in the form of a dashboard.

We’ve also updated the list of data points we track, to facilitate the ability to see how users interact with Symptom Checker. New events include search queries, transitions between screens (conversion funnel), and clicks on the body model.


We also refreshed the look of Symptom Checker. The changes are subtle, but they make the app even more visually appealing and easy to use.

Our previous text was centered, which looks nice but can be difficult to read so we’ve changed the text alignment to the left. What's more, icons, along with other elements of our design system, have been standardized. Their size and color are now consistent throughout the app. Also, since each color has its own meaning, we’ve stopped using colors to display certain icons (such as the green “Yes” icon) and condition probabilities (horizontal bars).

The side navigation panel may be hidden as needed to preserve screen space. However, since we still want to show the current progress of the interview, we’ve introduced a new flexible progress bar, which is usually located above each question.

Symptom Checker's new flexible progress bar.

To enhance user experience, we've introduced additional instructions. With the new tips (e.g., "Add at least one symptom"), it's much clearer what the app is asking for. We've also added new explanations (e.g., why Symptom Checker only allows you to choose between male and female) and edited a few headings (e.g., "Results" is now changed to "Possible conditions").


We want all Symptom Checker users to have equitable access to its information and functionalities. That's why, from now on, every feature is designed and implemented with accessibility in mind. We use the Web Content Accessibility Guidelines (WCAG 2.1) as a benchmark for these changes.

According to the WebAIM Million report for 2021, 86.4% of home pages have low-contrast text, making them hard for some users to read. Therefore, we’ve improved the contrast ratio between text and background, making it more readable for everyone.

In addition, we've increased the basic text size from 15 to 16 points and enlarged the interactive elements, such as links and buttons.

For people with vision loss, we've added labels and descriptions in the code for use with screen readers and other assistive devices. For users with disabilities that make it difficult to use a mouse or touchpad, our dynamic interview may be taken using only a keyboard. The blue border shows which item is currently active, demonstrating what is currently selected on the screen.

A blue border indicating an active item in the Symptom Checker.

The work on achieving full accessibility is not done yet, but we’re getting there. We also plan to educate our customers about accessibility, and why it is crucial to have accessible services.

Symptom Checker is now compliant with ISO-13485, the internationally recognized gold standard for quality in the medical device industry. This means our software development process is validated and certified by an external organization (in our case TÜV Nord). Read more about ISO-13485 certification.

To ensure the highest safety standards, a unique ID is assigned to each interview. Patients can now use it to completely erase their interview data. The unique ID can be found in the footer.

The role of body avatars in symptom checkers and how to work with them

Learn more about the role of body maps in symptom checking tools and best practices of building them.

Migrating to Symptom Checker 3

We hope this article has made you excited to use the latest version of our Symptom Checker. The migration will take place over the next few months for all our clients (with no request needed) and each customer will be notified in advance. We kindly inform you that previous versions will no longer be updated. We’d also like to assure you that the migration will be as seamless as possible, with little to no effort on your part.

If you can’t wait to explore the new features, please check the Symptom Checker Demo. We also invite you to give us feedback, as we want this app to serve you in the best way possible! Feedback can be provided at the end of a checkup.