10 Common Mistakes in Canvas Apps and How to Fix Them

Microsoft Power Apps allows users to design custom applications without deep coding knowledge. But even with its low-code interface, it's easy to fall into traps that can slow down performance, confuse users, or cause long-term maintenance headaches. Whether you're just getting started or you're scaling enterprise-level apps, here are ten common mistakes to avoid—plus actionable advice to fix them.

1. Overusing Global Variables

Global variables (Set()) are tempting due to their app-wide scope. However, excessive reliance on them can create bugs that are hard to trace. Because global variables persist across screens, changing them in one place can unintentionally affect logic elsewhere. This becomes especially problematic in apps with dynamic or conditional screens.

Fix: Use UpdateContext() for screen-level variables and only apply global variables when truly necessary. For lists or sets of records, consider using collections (ClearCollect()). These alternatives offer more localized control and are easier to debug.

Source URL: 10 Common Mistakes in Canvas Apps and How to Fix Them 

2. Ignoring App Performance Optimization

Loading too much data at once or using non-delegable functions with large data sources can grind your app to a halt. A common mistake is calling a data source like SharePoint or SQL without filters or pagination, forcing Power Apps to handle data locally.

Fix: Focus on delegation—Power Apps sends operations like filtering and sorting to the data source for more efficient processing. Use delegation-friendly functions (like Filter() instead of LookUp() where possible), and limit data calls on app startup. Always test app load time and responsiveness.

3. Inefficient Screen Navigation Logic

Hardcoding screen names into navigation functions like Navigate(Screen1) makes future updates cumbersome. As your app grows, managing screen transitions becomes a tangled mess.

Fix: Use a centralized navigation function or variable-based navigation pattern. For example, create a NavigateToScreen(screenName) function and use it across the app. This promotes consistency and simplifies navigation updates across multiple screens.

4. Poor Error Handling

Many developers assume everything will run smoothly and forget to handle errors gracefully. When something breaks—like a failed data submission—users often get vague or unhelpful error messages.

Fix: Implement IfError() to catch and display errors proactively. Use Notify() to alert users with friendly, actionable messages. Set up a global App.OnError property to catch and log unexpected issues for deeper debugging.

5. Hardcoding Values and Logic

Putting static values like URLs, display texts, or role checks directly into controls makes your app fragile and hard to update. If the business logic changes, you might need to update dozens of controls manually.

Fix: Store configuration values in a centralized SharePoint list, Excel file, or configuration table. Load them into a collection on app startup and reference them consistently. This approach simplifies updates and promotes reuse.

6. Not Using Reusable Components

Duplicating controls and logic across screens is inefficient and makes your app hard to maintain. Updating a repeated piece of UI in multiple places increases the chances of inconsistency.

Fix: Create reusable components with custom properties. Power Apps allows you to build your own UI blocks—like headers, menus, or forms—and reuse them throughout your app. For scalable projects, use component libraries to share them across multiple apps.

7. Inconsistent Design and UI/UX

Using random fonts, button styles, and color schemes on different screens results in a confusing and unprofessional interface. This inconsistency can hurt usability and adoption.

Fix: Define a style guide for your app. Create consistent font sizes, color themes, and control layouts. You can also build style templates using named variables for easy reusability. This ensures that your UI stays cohesive even as your app evolves.

8. Lack of Testing and Version Control

Deploying changes directly to a live app without proper testing can lead to user disruptions and data issues. Without version tracking, it’s difficult to roll back changes or collaborate with team members.

Fix: Use development and test environments before pushing updates to production. Leverage Power Platform’s solution layers to manage app versions and implement ALM (Application Lifecycle Management) practices. Tools like source control (e.g., Azure DevOps or GitHub) can also help track changes and manage releases.

9. Ignoring Accessibility Best Practices

Many Canvas Apps are built with no consideration for users who rely on keyboard navigation, screen readers, or color contrast. This exclusion not only limits usability but also violates accessibility standards.

Fix: Follow accessibility guidelines by using labels for every control, setting proper tab orders, ensuring sufficient contrast ratios, and testing your app with a screen reader. Make accessibility a default, not an afterthought.

10. Not Using Power Apps Monitor for Debugging

Testing apps only in Preview mode hides many behind-the-scenes performance issues and runtime errors. Developers often overlook Power Apps Monitor, which provides deeper insight.

Fix: Use the Power Apps Monitor tool to trace network activity, function calls, and errors during runtime. It allows you to see where performance bottlenecks occur, and which operations are slowing down your app. This is an essential tool for every serious developer.

Conclusion

Canvas Apps are powerful, but even small mistakes can spiral into major problems as your app scales. From overusing global variables to ignoring accessibility, the key to long-term success is proactive planning and adherence to best practices. Fixing these common issues doesn’t just improve your app’s performance—it also leads to better user adoption and easier maintenance.