Gallery Performance Optimization

Why Galleries Slow Down

Galleries can become sluggish due to:

• Too many controls per item
• Complex formulas in templates
• Large images or media
• Non-delegable data sources

Optimization Techniques

1. Limit Visible Items

// Instead of loading all records
Gallery.Items = DataSource

// Load a limited set
Gallery.Items = FirstN(DataSource, 50)

2. Simplify Gallery Templates

• Reduce controls to under 5 per item
• Avoid nested galleries
• Remove unnecessary borders and effects

3. Use DelayOutput on Search

SearchBox.DelayOutput = true
SearchBox.OnChange = // Don't need this anymore

This prevents the gallery from refreshing on every keystroke.

4. Cache Data with Collections

// Load once on app start
ClearCollect(colProducts, Products);

// Use collection in gallery
Gallery.Items = Filter(colProducts, StartsWith(Name, SearchBox.Text))

5. Optimize Images

• Use thumbnails instead of full images
• Set image control to Fit mode, not Fill
• Consider using image URLs instead of embedding

Loading Pattern

// Show loading indicator
Set(varLoading, true);
ClearCollect(colData, DataSource);
Set(varLoading, false);

// In your gallery
If(varLoading,
    ShowLoadingSpinner,
    Gallery
)

Measuring Performance

Use the Power Apps Monitor to identify slow operations:

1. Open your app in the editor
2. Go to Advanced tools > Monitor
3. Run the app and interact with galleries
4. Look for operations taking > 500ms

Rule of thumb: If your gallery has more than 3 controls or shows more than 100 items, consider optimization.