PNG vs SVG: When to Use Raster Images vs Vector Graphics
PNG and SVG get compared constantly, but they're not really two flavors of the same thing — PNG is a raster format that stores a fixed grid of colored pixels, and SVG is a vector format that stores mathematical instructions for drawing shapes. That difference in how each format actually works is what decides which one a given image needs, far more than which one happens to look better in a specific export.
PNG: a fixed grid of pixels
A PNG is, at its core, a grid of pixels with an exact color value assigned to each one, plus optional transparency through an alpha channel. That makes PNG the right choice for anything that's inherently pixel-based — a photograph, a screenshot, a scanned image, or any graphic with complex gradients and fine photographic detail that isn't reducible to clean shapes. The tradeoff is that a PNG is locked to the resolution it was saved at; scale it up significantly and the individual pixels start to show, producing a blurry or blocky result.
SVG: instructions, not pixels
An SVG file doesn't store pixels at all — it stores a set of instructions ("draw a circle here, this size, this color; draw a path along these points") written in XML text. A renderer reads those instructions and draws the image fresh at whatever size is needed, which means an SVG logo looks exactly as sharp on a small mobile icon as it does blown up across a billboard, with zero quality loss at any scale. This makes SVG the standard choice for logos, icons, and simple illustrations made of clean shapes, lines, and flat colors — anything that can genuinely be described as a set of shapes rather than as a grid of colors.
Why you can't just swap one for the other
SVG's advantage disappears the moment an image stops being describable as shapes — a photograph has no clean vector equivalent, so it has to be raster. Conversely, forcing a PNG to do a vector logo's job means baking in one specific resolution, so the same logo needs multiple exported PNG sizes for different uses (favicon, app icon, print) where a single SVG would have covered all of them. Neither format is simply "better"; they're built for genuinely different kinds of image content.
File size tells a similar story
For genuinely vector-appropriate content — a simple logo, an icon set, a line-art illustration — SVG files are typically far smaller than an equivalent PNG, since storing a handful of drawing instructions takes far less space than storing every individual pixel. For photographic or highly detailed content, that advantage flips entirely: SVG isn't built to describe a photograph's worth of detail, and attempting to would produce an enormous, impractical file. File size is a consequence of which format fits the content, not an independent reason to pick one over the other.
A quick way to decide
If the image is made of clean shapes, flat colors, and text — a logo, an icon, a simple illustration — it belongs as SVG. If the image has continuous tones, photographic detail, or came from a camera or a screenshot, it belongs as PNG (or another raster format). When you're handed the wrong one for the job — an SVG logo that needs to become a fixed-size PNG for a platform that doesn't accept vector uploads, for instance — SVG to PNG handles that conversion directly, and the image converter covers the rest of the common format pairs if you're working across formats beyond just these two. Once you have the right raster export, Compress Image can bring the file size down further if needed.