Raster vs Vector: What Every Designer Needs to Know

When you save an image as a PNG or JPG, you're working with a raster file. Each pixel is stored individually as a colour value. Zoom in far enough and you'll see the grid.

When you export an SVG or EPS, you're working with a vector file. Instead of pixels, it stores mathematical instructions — draw a curve from point A to point B, fill it with this colour, apply this stroke.

Why it matters

The practical difference shows up the moment you need to resize something.

A PNG logo at 200×200px looks fine on a business card. Blow it up to billboard size and it turns into a blurry mess — no amount of sharpening will recover information that was never there.

An SVG of the same logo can be scaled to any size — 20px for a favicon, 20 metres for a building wrap — with zero quality loss. The paths just recalculate.

When to use raster

• Photographs and complex images with millions of colour gradations
• Web images where file size matters more than scalability
• Anything that's already a bitmap and doesn't need to be reproduced at larger sizes

When to use vector

• Logos, wordmarks, and brand marks
• Icons, illustrations, and diagrams
• Anything that needs to appear at multiple sizes
• Files going to print, CNC, laser cutting, or vinyl plotters

Converting between formats

Raster → vector is a tracing operation. Software analyses the pixel regions and fits mathematical curves around them. The quality of the result depends on the source image complexity and the tracing algorithm.

Vector → raster is called rasterisation. It's predictable and lossless in one direction: any vector can be perfectly rasterised at any resolution. But once you rasterise, you can't recover the original paths — only a tracer can reconstruct them, and they'll never be identical.

That's why it's worth keeping master files in vector format from the start.