What is Optimistic UI?

An Optimistic User Interface is a design pattern to eliminate loading UI and give the users an instant response to their actions.

It’s a trick in simple words implemented by many developers to improve the UX of their apps.

In a traditional UI approach, when a user performs an action (such as submitting a form or updating a setting), the application waits for the server to process the request and then updates the UI based on the server’s response. This can lead to delays and a perceived sluggishness in the user experience.

In an optimistic UI approach, the application assumes that the action will succeed and immediately updates the UI to reflect the expected outcome. For instance, if a user submits a form to add an item, the application might immediately add the item to the UI’s list without waiting for confirmation from the server. If the server eventually confirms the action’s success, there’s no noticeable delay for the user.

A clear example can be found in a chat app where we submit a message and it immediately shows it in the UI and in a wallet app where we load or send the money, it may immediately change the balance on the UI without showing any loading spinners.

Here, both sending a message or money to someone may take some time even if it’s in milliseconds because the request has to go to the backend, and the data in the database is updated. But instead, we get the results immediately.

That’s the Optimistic UI where we get immediate responses to our interactions with the interface without any loading spinners, bars, or any kind of loading UI.

Here's a simple representation of how Optimistic UI works:

How is it implemented?

The UI holds fake but correct data until the request in the background is completed successfully. This is achieved by validating and calculating the data just after the user has interacted with UI (clicked a button or submitted data) and before or between the request is made to mutate the actual data in the database.

Doing this means we are being optimistic about the response from the server. So we give back the users an answer to their actions immediately by updating the UI with the data we predicted.

What if the request in the background fails?

It’s a rare case and most of the time it won’t because we are not going to push untested code to production but if it does the error should be handled in the most efficient way, the user must be notified about its failure, and the UI should be set back to its previous state.

---

Benefits & Drawbacks

Optimistic UI has both benefits and drawbacks.

Benefits:

1. Improved User Experience: The most significant advantage of optimistic UI is that it provides users with a more responsive and seamless experience. Interactions feel faster and more natural, leading to higher user satisfaction.
2. Reduced Perceived Latency: Since the UI updates immediately after the user’s action, users perceive less delay between their actions and the application’s response. This can create a perception of faster performance.
3. Engagement: Optimistic UI can encourage users to interact more frequently with the application, as the fluidity of the interface makes it more enjoyable to use.
4. Offline and Low Connectivity Support: Optimistic UI can work well in scenarios with intermittent or low connectivity. Users can continue interacting with the application even if they’re temporarily disconnected from the server, and their changes can be synchronized when the connection is restored.
5. Fewer Interruptive Alerts: Users may experience fewer interruptive alerts or confirmation dialogs, as the UI already assumes success. This can lead to a more streamlined and uninterrupted workflow.

Drawbacks:

1. Data Consistency: The most significant challenge with optimistic UI is maintaining data consistency between the client and server. If the server rejects an action that the client assumed would succeed, there’s a risk of data inconsistencies or conflicts that need to be resolved.
2. Error Handling Complexity: Handling errors becomes more complex in optimistic UI, as the application needs to detect and handle cases where the assumed success doesn’t align with the server’s response. This requires careful consideration and robust error-handling mechanisms.
3. User Confusion: If the UI assumes success and later reverts due to server rejection, users might be confused about the inconsistency between their expectations and the actual outcome.
4. Complex Synchronization Logic: Implementing proper synchronization logic to handle successful updates and rollbacks can be challenging. This complexity can increase the development effort and the potential for bugs.
5. Network and Server Reliability: Optimistic UI relies on the assumption that the server will eventually confirm the action’s success. If there are network issues, server errors, or other reliability problems, users might experience unexpected behavior or data discrepancies.
6. Security Concerns: Depending on the application’s nature, assuming success without proper validation from the server could potentially lead to security vulnerabilities or unauthorized actions.

In summary, optimistic UI can greatly enhance user experience and engagement in real-time or near-real-time applications. However, it requires careful planning, robust error handling, and synchronization mechanisms to ensure data consistency and avoid confusing or misleading users. The decision to adopt an optimistic UI approach should be based on the specific needs of the application and its user base.

If you have liked my writing do support me on my BMC page. Thank you for Reading.