Vector vs Raster Graphics: Which to Use?

In the world of digital design, one of the most fundamental decisions is choosing between vector and raster graphics. Each format type has distinct characteristics that make it ideal for specific use cases. Understanding these differences is crucial for designers, developers, and anyone working with digital images.

In this comprehensive guide, we'll explain the technical differences between these format types, explore their advantages and limitations, and provide clear guidance on when to use each for optimal results.

Understanding Vector Graphics

Vector graphics are defined by mathematical equations—points, lines, curves, and shapes—rather than individual pixels. This fundamental difference gives vectors their most important characteristic: infinite scalability.

How Vector Graphics Work

According to MDN Web Docs, vector graphics store image data as geometric shapes defined by mathematical formulas. When you zoom in or scale up a vector image, the computer simply recalculates the equations to render the image at the new size.

A simple vector circle might be defined as:

<svg width="100" height="100">
  <circle cx="50" cy="50" r="40" fill="blue" />
</svg>

This circle can be rendered at any size—from a tiny icon to a billboard—without any quality loss.

Common Vector Formats

• SVG (Scalable Vector Graphics): The web standard for vector graphics, supported by all modern browsers. W3C specification.
• AI (Adobe Illustrator): Adobe's proprietary format for professional design work.
• EPS (Encapsulated PostScript): Legacy format still used in print workflows.
• PDF: Can contain vector elements, widely used for documents and print.

Advantages of Vector Graphics

• Infinite Scalability: Scale to any size without quality loss
• Small File Size: For simple graphics, vectors are typically smaller than rasters
• Editability: Individual elements can be easily modified
• CSS Styling: SVGs can be styled and animated with CSS
• Accessibility: Text in SVGs remains selectable and searchable

Limitations of Vector Graphics

• Not Suitable for Photos: Cannot represent complex photographic detail
• Complexity Issues: Very detailed vectors can become large and slow to render
• Creation Requires Skill: Designing vectors requires specialized software and skills

Understanding Raster Graphics

Raster graphics (also called bitmap images) consist of a fixed grid of pixels, each containing specific color information. The number of pixels determines the image resolution and, consequently, the maximum size at which the image can be displayed clearly.

How Raster Graphics Work

A raster image is essentially a mosaic of tiny colored squares. A 1920x1080 image contains over 2 million pixels, each with its own color value. This pixel-based approach allows rasters to capture the subtle gradations and complex details found in photographs.

Common Raster Formats

• AVIF: The most efficient modern format with 30-50% better compression than JPEG. See our AVIF guide.
• WebP: Google's format with good compression and wide browser support.
• JPEG/JPG: Universal support, best for photographs, no transparency.
• PNG: Lossless compression with transparency support, ideal for graphics with text.
• GIF: Limited to 256 colors, supports animation.
• TIFF: High-quality format used in professional photography and print.

Advantages of Raster Graphics

• Photographic Detail: Captures subtle color gradations and complex textures
• Universal Support: Raster formats work everywhere
• Easy to Create: Any camera or screenshot creates raster images
• Effects and Filters: Extensive photo editing capabilities

Limitations of Raster Graphics

• Resolution Dependent: Quality degrades when enlarged beyond native resolution
• Larger File Sizes: High-resolution images can be very large
• Limited Editability: Cannot easily modify individual elements

Vector vs Raster: Direct Comparison

When to Use Each Format

Use Vector Graphics (SVG) For:

• Logos and Branding: Need to work at any size from favicon to billboard
• Icons: UI icons, social media icons, navigation elements
• Illustrations: Simple to moderately complex artwork
• Infographics: Charts, graphs, data visualizations
• Animated Graphics: SVG animations with CSS or JavaScript
• Responsive Design: Graphics that need to adapt to different screen sizes

Use Raster Graphics (AVIF/WebP/PNG/JPG) For:

• Photographs: Always use raster for photos
• Complex Artwork: Digital paintings with gradients and textures
• Screenshots: UI screenshots, software documentation
• Product Images: E-commerce product photos
• Textures and Patterns: Complex visual textures
• Photo Manipulations: Composites and edited photographs

Real-World Use Cases

Website Design

For a typical website, you'll use both:

• Logo: SVG (scales perfectly in header, footer, favicon)
• Navigation Icons: SVG (can be styled with CSS)
• Hero Images: AVIF/WebP with JPEG fallback
• Product Photos: AVIF/WebP with JPEG fallback
• Blog Images: AVIF/WebP with JPEG fallback
• Social Media Icons: SVG (consistent styling)

Mobile App Development

According to Android Developer documentation, vector drawables are recommended for icons and simple graphics because they scale perfectly across all screen densities:

• App Icons: Vector for adaptability
• UI Elements: SVG/Vector Drawable
• User Content: Raster (photos, uploads)
• Illustrations: Vector when possible

Print Design

Print design often requires higher resolutions:

• Logos: Vector (EPS, AI, or PDF)
• Photographs: High-resolution raster (300+ DPI TIFF or PSD)
• Text Elements: Vector for crisp printing
• Background Textures: High-resolution raster

Converting Between Formats

Raster to Vector (Tracing)

Converting raster to vector requires "tracing" the image. Tools include:

• Inkscape's Trace Bitmap (free)
• Adobe Illustrator's Image Trace
• Online vectorizers like Vectorizer.io

Note: Tracing works best with simple graphics with clear edges. Photographs cannot be meaningfully converted to true vectors.

Vector to Raster (Rasterizing)

Converting vector to raster is straightforward—simply export at the desired resolution. Our AVIF to SVG converter can help with certain conversions, though keep in mind that raster-to-vector conversion has limitations.

Optimizing Each Format Type

Optimizing SVG Files

• Use SVGOMG to compress and optimize SVGs
• Remove unnecessary metadata and editor information
• Simplify paths and reduce decimal precision
• Consider using sprite sheets for multiple icons

Optimizing Raster Images

• Choose the right format (AVIF > WebP > JPG/PNG)
• Compress to appropriate quality levels (80-85% for most uses)
• Resize to the actual display dimensions
• Use responsive images with srcset

For more optimization techniques, see our complete image optimization guide.

Decision Framework

Use this quick decision framework:

Conclusion

Both vector and raster graphics have essential roles in digital design. Vectors excel at scalability and crisp lines, making them perfect for logos, icons, and illustrations. Rasters capture photographic detail and complex color variations that vectors cannot represent.

The best approach is usually to use both formats strategically: vectors for UI elements and branding, rasters for photographs and complex images. By understanding the strengths and limitations of each, you can make informed decisions that result in better-looking, faster-loading, and more accessible content.

Ready to convert your images? Try our tools:

• Convert AVIF to SVG
• Convert AVIF to PNG
• Convert AVIF to JPG