What Is Smart Compression?

Purpose:
Smart Compression is designed around how different image sizes are actually used on a website.

• Small images (e.g. ≤50KB) need to stay sharp.
  Even slight quality loss can be noticeable at small sizes.
• Medium images (e.g. 50KB< Size< 4MB) are often shown inline and loaded frequently.
  Smart Compression balances visual quality and file size to improve page loading speed.
• Large images (e.g. ≥4MB) usually take up the most disk space.
  They can be compressed more efficiently to save storage, while still remaining visually sharp and fast to load.

Instead of using a single fixed quality for all images, Smart Compression dynamically adjusts compression quality based on image size.

When Should You Change These Settings?

Default Settings Are Enough If:

• You run a typical website
• You want good quality with minimal configuration
• You don’t handle extremely large images

Consider Custom Settings If:

• You host very large images (photography, portfolios)
• You want aggressive optimization for performance
• You need different quality behavior for WebP and AVIF

Smart Quality Rules

Smart Compression is controlled by a set of rules that define how compression quality changes as image size increases.

1. Size Threshold

What Is the Size Threshold?

The Size Threshold defines the split point between:

• Fixed compression (small images).
• Adaptive compression (large images)

Mathematica:
Images ≤ Threshold → Fixed quality
Threshold ≤ Images < Threshold → Adaptive quality
Images ≥ 4MB → Fixed quality

2. Small Images (≤ Threshold)

How Small Images Are Compressed?
Images smaller than or equal to the threshold use a fixed compression quality.
The 4MB threshold is based on practical testing and real-world usage feedback.
Images larger than this size usually benefit from stronger compression with little noticeable quality loss.

**This value may be fine-tuned over time.
Settings

• WebP Fixed Quality.
• AVIF Fixed Quality.

Why Fixed Quality?

• Prevents visible degradation on icons, logos, and UI elements.
• Ensures consistent visual appearance.

These values are applied directly without any adaptive adjustment.

3. Larger Images (> Threshold)

Large images use adaptive compression.
Compression quality decreases automatically as image size increases.

How Quality Changes?
Quality decreases smoothly from 95 to 28 (changeable) between the threshold and 4MB.
This means:

• Smaller large images retain higher quality.
• Larger images receive stronger compression.

Threshold → 4MB
Quality: 80 → 35
Lower quality = smaller file size

4. Quality ≥ 4MB

Maximum Compression for Very Large Images
Images larger than or equal to 4MB use the minimum quality value.

• This value is controlled by the slider.
• Ensures very large images are compressed aggressively.

This prevents oversized images from harming page performance.

5. WebP and AVIF Differences

Smart Compression allows separate control for:

• WebP
• AVIF

Each format has its own:

• Fixed quality
• Adaptive quality range
• Minimum quality

This reflects real-world differences in compression efficiency between formats.

6. Visual Quality Curve

The chart at the bottom visualizes how compression quality changes as image size increases.

What the Chart Shows:

• X-axis: Image file size
• Y-axis: Compression quality
• Separate curves for WebP and AVIF

Why the Curve Matters:

• Confirms that quality decreases gradually
• Helps users understand compression behavior
• Ensures there are no sudden quality drops

Summary

Smart Compression provides:

• Fixed quality where it matters
• Adaptive compression where it’s safe
• Clear, predictable behavior
• Full control for advanced users

It is designed to work well out of the box while remaining fully configurable when needed.