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svg_viewbox

What is viewBox?

• Defines the visible region of the SVG’s internal coordinate system.
• Syntax: viewBox="<min-x> <min-y> <width> <height>"
• Think of it like a camera: it determines what part of the canvas is visible, not the actual size of the SVG.

How Responsiveness Works

• viewBox enables the SVG to scale independently of pixel size.
• Changing the SVG's width or height scales the contents defined within the viewBox.
• Internal elements remain consistent relative to the viewBox dimensions.

Example Concept:

• SVG with viewBox="0 0 100 100" and width="300":
  • A shape with width 100 will render as 300px wide.
• Changing width to 500 scales the entire content proportionally.

Key Concept: viewBox ≠ Size

• viewBox affects coordinate system, not rendered size.
• Size is controlled by the width and height attributes.

Aspect Ratio Behavior

• The default aspect ratio is inferred from the viewBox.
• If only width or height is provided:
  • Browser preserves the viewBox aspect ratio to calculate the missing dimension.

To override:

• Set both width and height explicitly.

preserveAspectRatio Attribute

Purpose	Example Value	Behavior
Anchor viewBox	xMidYMid	Centers content in the available space
Scale mode: preserve or crop	meet / slice	meet: fit all content; slice: fill & crop

• preserveAspectRatio affects how the viewBox is fitted into the space defined by width and height.

Summary

• viewBox sets up a scalable coordinate space.
• width/height control rendered size.
• SVGs scale their content based on the ratio between viewBox and output size.
• preserveAspectRatio fine-tunes how content is aligned and scaled.

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