A clear explanation of raster and vector graphics — how each format works, their strengths, limitations, file sizes, and best use cases.

Every digital image you have ever seen falls into one of two categories: raster (also called bitmap) or vector. Understanding the difference between these two types is fundamental to working with digital graphics — whether you are a designer, developer, photographer, or someone who just wants to know why your logo looks blurry on a banner.

What Are Raster Graphics?

A raster image is a grid of pixels. Each pixel is a tiny square of a single color. When you zoom out, your brain blends these tiny squares into a continuous image — just like a mosaic made of colored tiles looks like a picture when viewed from a distance.

Every photograph you have taken with a phone or camera is a raster image. When your camera captures a 12-megapixel photo, it is recording a grid of 12 million individual color values. Common raster formats include JPEG, PNG, GIF, WebP, BMP, and TIFF.

The key property of raster images is that they have a fixed resolution. A 1000×1000 PNG contains exactly one million pixels. If you display it at its native size, it looks sharp. If you stretch it to 5000×5000 pixels, each original pixel becomes a 5×5 block, and the image looks blurry and pixelated.

What Are Vector Graphics?

A vector image is a set of mathematical instructions that describe shapes. Instead of storing "pixel at position (100,50) is red," a vector image stores "draw a circle at position (100,50) with radius 30, filled with red." The rendering engine (browser, printer, or display driver) interprets these instructions and draws the shapes at whatever resolution the output device requires.

Because the instructions are mathematical, they can be evaluated at any scale. Tell the engine to draw that circle at 10 pixels wide or 10,000 pixels wide — it recalculates the geometry and the result is always perfectly smooth. There is no "native resolution" to exceed. Common vector formats include SVG, AI (Adobe Illustrator), EPS, and PDF (which can contain both vector and raster elements).

The Fundamental Trade-off

Raster graphics can represent any image — photographs, paintings, textures, noise, anything that can be displayed as a grid of colors. There is no image too complex for a raster format to store.

Vector graphics can represent structured shapes efficiently — curves, polygons, text, and geometric patterns — but struggle with continuous-tone imagery like photographs. Trying to represent a photograph as vector paths would require millions of tiny shapes, resulting in a file many times larger than the raster original with no quality benefit.

When Raster Wins

  • Photography — camera output is inherently raster
  • Complex natural imagery — landscapes, textures, skin tones, food
  • Screenshots — pixel-perfect representation of screen content
  • Pixel art — deliberate pixel-level control

When Vector Wins

  • Logos — must work at every size from favicon to billboard
  • Icons — clean shapes that need to be crisp at small sizes
  • Typography — every font on your computer is stored as vector outlines
  • Illustrations — flat or line-style artwork
  • Charts and diagrams — data visualization with clean lines and text
  • Print design — anything that will be printed at high resolution
  • Animation and interactivity — SVG elements can be individually animated

File Size Differences

For a simple three-color logo, the SVG file might be 3 KB while a high-resolution PNG of the same logo could be 50 KB. The vector format is smaller and sharper.

For a photograph of a sunset, a JPEG might be 200 KB while an SVG attempting to represent the same image could be 20 MB. The raster format is dramatically smaller and more appropriate.

Converting Between Raster and Vector

Raster to vector (vectorization): Tools like Shape to Vector analyze the pixels in a raster image and trace the boundaries of colored regions to produce vector paths. This works well for flat-color graphics but not for photographs.

Vector to raster (rasterization): Any vector image can be converted to raster at any resolution — just export from your vector editor or render in a browser and take a screenshot. This direction is lossless at any target resolution.