🔍 What to Observe While Scrolling

1. Always Active (0) - Green Header

This header activates the scroll-in effect at any scroll speed, even the gentlest upward movement. It provides maximum responsiveness and accessibility.

• Pros: Most responsive and accessible for all users
• Cons: May activate during accidental tiny scroll movements
• Best for: General-purpose headers, maximum accessibility

2. Low Threshold (2) - Blue Header

Requires minimal scroll speed to activate. Still very responsive but filters out the tiniest movements.

• Pros: Responsive while filtering micro-movements
• Cons: Slight reduction in activation sensitivity
• Best for: Desktop interfaces, content-heavy sites

3. Medium Threshold (10) - Orange Header

Requires moderate scroll speed for activation. Creates more intentional user interaction patterns.

• Pros: Prevents accidental activation, intentional interactions
• Cons: Less responsive to slow, gentle scrolling
• Best for: Professional sites, focused reading experiences

4. High Threshold (25) - Red Header

Only activates during fast, deliberate scroll movements. Creates a minimalist, distraction-free experience.

• Pros: Completely distraction-free, only appears when truly needed
• Cons: May be less accessible for some users
• Best for: Immersive content, portfolio sites, minimal interfaces

🧪 Try These Scroll Speed Tests

Ultra-slow scrolling: Only the green (0) and possibly blue (2) headers should activate.

Gentle scrolling: Green (0) and blue (2) headers activate, orange (10) might not.

Moderate scrolling: Green (0), blue (2), and orange (10) headers should activate.

Fast scrolling: All headers including red (25) should activate the scroll-in effect.

Mouse wheel vs trackpad: Notice how different input methods affect activation.

🎯 Understanding ScrollThreshold Behavior

The scrollThreshold parameter measures scroll speed in pixels per scroll event:

How it works:

• When scrolling up, the script measures: -scrollStep >= scrollThreshold
• scrollStep = current scroll position - previous scroll position
• Higher threshold = more pixels required per scroll event = faster scrolling needed
• Once activated, headers position themselves above viewport to scroll into view naturally

Input method differences:

• Mouse wheel: Discrete scroll events, consistent pixel amounts
• Trackpad: More granular control, easier to hit lower thresholds
• Touch devices: Flick gestures can easily hit high thresholds
• Keyboard navigation: Page Up creates large scroll steps

🎨 Design Pattern Recommendations

Choose scrollThreshold: 0 when:

• Accessibility is your top priority
• Building interfaces for diverse user abilities
• Header contains critical navigation elements
• Users expect immediate responsiveness

Choose scrollThreshold: 2-5 when:

• You want to filter out accidental micro-movements
• Building desktop-focused applications
• Header activation should feel slightly more deliberate
• Balancing responsiveness with intentionality

Choose scrollThreshold: 10-15 when:

• Creating more intentional user interaction patterns
• Building professional or corporate websites
• Header should only appear during active navigation
• Reducing visual distractions during content consumption

Choose scrollThreshold: 20-30+ when:

• Designing immersive, distraction-free experiences
• Building portfolio or gallery websites
• Header should only appear with clear navigational intent
• Minimalist design philosophy where less is more

📝 Implementation

Setting scrollThreshold is straightforward:

// Always activate (maximum responsiveness)
naturalStickyTop(element, { scrollThreshold: 0 });

// Low threshold (gentle filtering)
naturalStickyTop(element, { scrollThreshold: 2 });

// Medium threshold (balanced approach)
naturalStickyTop(element, { scrollThreshold: 10 });

// High threshold (intentional activation only)
naturalStickyTop(element, { scrollThreshold: 25 });

// Combine with snapEagerness for full control
naturalStickyTop(element, { 
  scrollThreshold: 10,  // Moderate activation requirement
  snapEagerness: 1.5    // Slightly eager gap prevention
});

🔄 Comparing with SnapEagerness

Understanding how scrollThreshold and snapEagerness work together:

• scrollThreshold controls when the scroll-in effect activates
• snapEagerness controls how the element transitions to sticky positioning
• Both parameters work together to create the complete user experience
• You can mix and match: high threshold + low eagerness, or low threshold + high eagerness

Continue scrolling to keep testing all four threshold behaviors simultaneously!

This unified scrolling experience makes it immediately clear how different scrollThreshold values respond to your actual scrolling patterns. No need to test each demo separately!