PNG vs JPG: Which Should You Actually Use?

PNG and JPG are the two formats almost everything on the internet uses, and picking the wrong one costs you either file size or image quality. The choice isn’t complicated once you know the single question that decides it.

The question that decides it

Does the image have large areas of flat colour and sharp edges, or is it a photograph?

Sharp edges and flat colour — screenshots, logos, diagrams, text, line art, anything with transparency — want PNG.

Photographs and anything with continuous gradients — people, landscapes, product shots — want JPG.

That single rule gets you the right answer the overwhelming majority of the time. The rest of this explains why, and what to do at the edges.

How they differ

JPG (JPEG) is lossy. It permanently discards image data to save space, exploiting the fact that human eyes are more sensitive to brightness than to fine colour detail. You choose how aggressive that discarding is via a quality setting. The data it throws away never comes back.

PNG is lossless. It compresses without discarding anything — decompress a PNG and you get back the exact pixels you started with. It also supports transparency, which JPG does not, and that alone decides many cases.

The size difference is dramatic and runs in both directions:

• A 12-megapixel photograph might be 3 MB as a JPG and 25 MB as a PNG.
• A screenshot of a spreadsheet might be 200 KB as a PNG and 400 KB as a JPG — while also looking worse.

Neither format is “better”. They’re optimised for different kinds of image.

Why JPG ruins screenshots

JPEG’s compression works by breaking the image into blocks and simplifying each one. This is nearly invisible on a photograph, where detail is irregular. It’s very visible on a screenshot, where you have crisp black text on flat white.

Compress that with JPEG and you get faint grey smudging around every letter — “ringing” artefacts — plus blotchy patches in areas that should be perfectly uniform. Text goes from crisp to slightly grubby. And because screenshots have so much flat colour, JPEG often produces a larger file than PNG while looking worse. You lose on both counts.

If you’ve ever seen a screenshot that looked slightly dirty around the text, this is what happened to it.

Why PNG bloats photographs

PNG’s lossless compression works by finding patterns and repetition. Photographs have almost none — every pixel differs slightly from its neighbour because of sensor noise, texture and natural variation. PNG faithfully preserves all of it, including noise nobody wants, and the file becomes enormous.

Saving a photo as PNG typically produces a file several times larger than a high-quality JPG that looks identical.

A practical lookup

Use PNG for: screenshots, logos and icons, diagrams and charts, images with transparency, line art, images containing text, pixel art, anything you’ll edit repeatedly, and images where exact colour accuracy matters.

Use JPG for: photographs, email attachments where size matters, images for upload forms with size limits, large galleries, and anything where a small quality loss is invisible but the space saving isn’t.

Use neither — consider WebP for: modern websites, where it typically beats both. Its weakness is compatibility outside browsers, which is why our WebP converter exists: images saved from the web are often WebP, and plenty of desktop software still can’t open them.

Converting between them sensibly

PNG to JPG makes sense when you have a photograph mistakenly saved as PNG, or when you need to hit an upload size limit. Our PNG to JPG converter handles this. The size reduction can be enormous — a photographic PNG often drops by 80–90%.

One thing to watch: JPG has no transparency. Converting a PNG with a transparent background means those areas must become something solid. Our converter fills them with white, which is the sensible default for most uses — but if you’re converting a logo intended to sit on a coloured background, you’ll get a white box around it. In that case, keep the PNG.

JPG to PNG is more limited than people expect, and it’s worth being blunt about why. Converting a JPG to PNG does not restore quality. The data JPEG discarded is gone permanently; PNG just preserves the damaged version losslessly, in a much bigger file.

It’s genuinely useful when you need a format that won’t degrade further through repeated editing and saving, when software you’re using demands PNG, or when you need to add transparency to an image that started as a JPG. Our JPG to PNG converter does this — just don’t expect it to undo compression that already happened.

Generational loss: the real trap

Every time you save a JPG, it re-applies lossy compression. Open a JPG, crop it, save it — that’s a second generation. Do that repeatedly and the degradation accumulates visibly: blockiness in smooth areas, haloes around edges, colours drifting.

PNG doesn’t have this problem. Saving a PNG a hundred times gives you the same pixels a hundred times.

The practical rule: if an image is still being worked on, keep it in a lossless format. Convert to JPG once, at the very end, when it’s final. And always keep the original — the mistake that hurts is deleting your only copy after converting.

Quality settings, briefly

When saving JPG you’ll be asked for a quality value, usually 0–100.

Quality 100 preserves detail nobody can perceive and produces needlessly huge files. Around 80–85 is the sweet spot for most photographs — a large size reduction versus maximum quality with differences almost nobody notices at normal viewing sizes. Below 60 you start seeing genuine artefacts.

Our converters default to 82 for this reason, and show you the before-and-after size for every file so you can see immediately what your setting costs.

The short version

Photographs go to JPG. Screenshots, logos, diagrams and anything with transparency go to PNG. Converting a photo from PNG to JPG saves a great deal of space for no visible loss. Converting a JPG to PNG doesn’t recover anything, but does stop further degradation. And whatever you do, keep your originals.