As your Power Apps projects become more sophisticated, you'll quickly encounter situations where multiple screens need access to the same information. Instead of repeatedly looking up data or passing values between screens, you can store information in a global variable.

What Is a Global Variable?

A global variable is a temporary container that stores information while your Canvas App is running.

Unlike a label or text input, a global variable isn't visible to users. Instead, it works behind the scenes to remember values that your app can use anywhere.

Think of it as a sticky note your app carries from one screen to another.

Examples include:

• Current logged-in employee

• Selected equipment

• Active work order

• Current language

• User permissions

Once a value is stored, every screen in your app can access it until the app is closed.

Business Scenario

Imagine your company has an Equipment Checkout application.

An employee opens the app and selects a laptop from a gallery.

Instead of searching for that laptop again on the next screen, you'll save its information in a global variable.

The variable will store:

• Equipment ID

• Equipment Name

• Asset Tag

• Assigned Employee

Every screen can then use this information without asking the user to select the item again.

Step 1: Create the Gallery

Suppose your SharePoint list contains the following columns:

Display these records in a gallery.

Each gallery item represents one piece of equipment.

Step 2: Save the Selected Equipment

When a user selects a gallery item, store the entire record in a global variable.

Using a record instead of storing each field individually keeps your formulas cleaner and makes future updates easier.

Now your app remembers exactly which equipment the user selected.

Because the variable is global, any screen can reference it immediately.

Step 3: Display the Information

On the Equipment Details screen, use the stored variable to populate labels.

For example, display:

• Equipment Name

• Asset Tag

• Status

• Assigned Employee

Notice that no additional SharePoint lookup is required.

The information is already available because it was stored when the user selected the equipment.

This makes navigation feel much faster.

Step 4: Update the Variable

Suppose the employee checks out a different laptop.

When they select another gallery item, simply update the same global variable.

There's no need to delete the old value first.

The new selection automatically replaces the previous one.

This makes global variables ideal for tracking the user's current selection throughout an application.

Beyond Text Values

Global variables aren't limited to text.

They can store many different types of information, including:

• Numbers

• Dates

• Boolean values

• Records

• Tables

For example:

• Store today's date after a successful inspection.

• Save whether dark mode is enabled.

• Remember the current user's department.

• Cache a record that multiple screens need.

This flexibility allows you to reduce repeated calculations and unnecessary data lookups.

Common Use Cases

Global variables are especially useful for:

User Information

Store the current user's email, department, or role after the app loads.

Every screen can reference the same information.

Navigation

Remember which record the user selected before moving to another screen.

Application Settings

Store values such as:

• Theme color

• Language

• Default location

• Currency

This avoids repeating the same formulas throughout your app.

Temporary Results

You might calculate:

• Total inventory value

• Remaining budget

• Inspection score

Instead of recalculating the value repeatedly, save it once and reuse it.

When Not to Use Global Variables

Although they're powerful, global variables aren't always the right choice.

Avoid using them when:

• A formula can calculate the value automatically.

• The value only belongs to one screen.

• The information should always come directly from the data source.

Remember that variables don't update themselves if the original data changes. If your SharePoint record is modified after you store it in a variable, you'll need to refresh or assign the updated value again.

Best Practices

To keep your apps maintainable:

• Use descriptive variable names.

• Store complete records when appropriate instead of dozens of individual values.

• Reuse existing variables rather than creating new ones for the same purpose.

• Clear variables when they are no longer needed.

• Keep variable names consistent throughout your application.

A naming convention such as:

• varSelectedEquipment

• varCurrentUser

• varInspectionScore

• varManagerEmail

makes your formulas much easier to understand.

Common Mistakes

Creating Too Many Variables

If every control has its own variable, your app quickly becomes difficult to maintain.

Instead, create variables only when multiple screens or multiple formulas need the same value.

Forgetting That Variables Are Temporary

Global variables exist only while the app is running.

Closing the app removes them.

If information must be saved permanently, write it back to your data source instead.

Storing Outdated Data

If another user updates a SharePoint record, your variable won't automatically reflect those changes.

Refresh or reassign the variable whenever fresh data is required.

Why Variables Improve Performance

Using variables can reduce repetitive lookups against SharePoint or Dataverse.

Instead of requesting the same information multiple times, your app retrieves it once and reuses it.

Benefits include:

• Faster screen transitions

• Cleaner formulas

• Better readability

• Easier maintenance

• Reduced duplicate logic

The key is using variables strategically—not everywhere.

Conclusion

Global variables are one of the simplest ways to build responsive and maintainable Power Apps. By storing important information—such as the currently selected equipment, logged-in user, or application settings—you can reduce repetitive formulas and make navigation smoother.

As you build larger Canvas Apps, you'll find that well-planned variables help organize your logic and improve the overall user experience. Use them where shared, temporary state makes sense, and combine them with Power Apps' formula-driven approach for apps that are both efficient and easy to maintain.