PNG vs JPG: Which Format to Choose and Why It Matters

The short answer in 30 seconds

If you don't have time for the whole thing, here's the rule that covers 95% of cases:

• Photograph (people, nature, food, smooth color gradients) → JPG. The file will be many times smaller, and your eye won't spot the difference from the original.
• Graphics (logos, icons, diagrams), screenshots, text, or you need transparency → PNG. Sharp edges stay perfectly crisp, with no fuzz or halos.

That's it. The rest of this guide explains why that works — with numbers and clear examples. Once you grasp the mechanics, you'll choose confidently even in the borderline cases.

The core difference: lossy vs lossless

The entire gap between the two formats grows from one thing: how they compress an image. Get this, and everything else falls into place.

JPG uses lossy compression. To make the file small, it literally throws away some data — the details your eye barely registers. Technically, it splits the image into 8×8-pixel blocks, converts them into a set of frequencies, and discards the "high frequencies" (the sharp color transitions). On a photo, with its soft gradients, that's invisible. But what's discarded can't be recovered — hence the word "lossy."

PNG uses lossless compression. It runs the same DEFLATE algorithm as ZIP archives: it finds repeating patterns and encodes them more compactly, but loses not a single pixel. What goes in comes out, bit for bit. That's why PNG is perfect wherever absolute precision matters: text, thin lines, flat areas of color.

PNG vs JPG: the comparison table

Here's the whole difference on one screen, criterion by criterion. Keep this table handy whenever you're unsure.

Size and quality: who wins where

This is where intuition breaks. Many assume PNG is "always higher quality, and JPG is always lighter." In reality it all depends on the content of the image.

Take an ordinary 4000×3000-pixel photograph. Uncompressed, that's around 36 MB. Compare how the formats squeeze it:

On a photograph, JPG wins by a landslide: about 8× lighter than PNG at a quality your eye can't tell from the original. That's exactly why cameras, messengers and social networks all default to JPG.

Now take flat graphics instead — a logo or diagram, 800×600, with even fills of color. The picture flips: PNG squeezes it to roughly 25 KB, while JPG bloats it to around 60 KB — larger in size and worse in quality, with visible fuzz on the edges. On this kind of content, JPG's strength becomes its weakness.

Transparency: why logos are PNG

This is the deciding argument, and often the one that settles the choice on its own. JPG cannot do transparency at all. It always has a solid, rectangular background.

PNG supports an alpha channel — a separate layer that defines, for every pixel, how transparent it is: from fully visible to fully invisible, and any level in between. That's what lets a PNG logo or icon sit on a page of any color, with its edges blending neatly into the background.

So what happens if you save a transparent logo as JPG? The transparent areas get filled with solid white (or whatever the background color is). Drop that "logo" onto a dark page and you'll get an ugly white rectangle around it. Hence the simple rule: if you need transparency, it's always PNG (or WebP, more on that below).

JPG artifacts: where the fuzz on text comes from

If you've ever saved a screenshot as JPG, you've seen the result: murky colored halos appear around black letters on a white background, and thin lines "ring" and smear. It's not a bug — it's the natural consequence of how JPG works.

Remember those discarded "high frequencies"? A sharp boundary between a black letter and a white background is a high frequency in its purest form. JPG tries to average it out, and where there was a crisp edge you now get a zone of blurry mid-tones. Photos have few such sharp boundaries, so the artifacts don't jump out. But text, a UI screenshot or a line drawing have sharp boundaries everywhere — and every one of them grows a layer of fuzz.

What about WebP?

A fair question: if each format has its weak spots, isn't there something better? For the web, there is. It's WebP, from Google.

WebP is a hybrid that took the best of both worlds. It does lossy compression (like JPG), lossless (like PNG), plus transparency (like PNG) and animation. And its files are typically 25–35% smaller than JPG, and noticeably smaller than PNG, at comparable quality. For page-load speed that's a direct win.

So where's the catch? In compatibility. Modern browsers understand WebP, but many older programs, editors and devices don't. Send a colleague a WebP to review, and they may not be able to open it in their usual app.

How to convert both ways

Often a file already exists in the "wrong" format and needs converting. It's easy, but each direction has its own catch.

The full list of conversions — from JPG to PNG to PNG to WebP — is always on the all formats page. And if you want to understand PNG itself more deeply, see our guide "What is PNG".