JPG vs PNG: which format should you use?
Short answer: Use JPG for photographs, where its compression makes files several times smaller with no difference you can see. Use PNG for screenshots, logos, diagrams and anything with text, sharp edges or a transparent background, where JPG's compression leaves smudges. If the image is for a website, WebP usually beats both.
Updated
The one difference that matters
JPG (also written JPEG) is a lossy format. When a JPG is saved, the encoder throws away detail it predicts you will not notice — subtle colour variation, fine texture — and that is how it gets photographs so small. The loss is permanent: nothing can bring the discarded detail back.
PNG is lossless. It stores every pixel exactly, then packs the result as tightly as it can without changing anything. What goes in is precisely what comes out, however many times the file is opened and saved again.
Almost every practical difference follows from that. JPG is small and slightly approximate; PNG is exact and usually larger. Which one is right depends on whether the approximation shows.
Side by side
| JPG | PNG | |
|---|---|---|
| Compression | Lossy | Lossless |
| Transparency | No | Yes, a full alpha channel |
| Photograph file size | Small | Commonly 2–5× the JPG |
| Screenshot and text quality | Soft edges, visible artefacts | Pin-sharp |
| Quality after repeated saves | Degrades a little each time | Unchanged |
| Opens everywhere | Yes | Yes |
When JPG is the right choice
Photographs are what JPG was designed for, and it is very good at them. A photo is full of gradual changes in colour and texture, which is exactly the kind of detail JPG can simplify without anyone seeing the difference. At a quality setting around 85, a JPG of a typical phone photo is indistinguishable from the original at normal viewing size.
- Photos you are emailing, uploading to a form or posting online.
- Images for print where file size matters and there is no transparency.
- Anywhere a site or application asks specifically for JPG — many upload forms still do.
If you have a photograph saved as PNG — a screenshot of a photo, or an export from an editor — converting it to JPG typically cuts the file by 70–90% with no visible change.
When PNG is the right choice
JPG struggles with hard edges. Around text, lines and flat areas of colour it produces faint ripples and blotches — compression artefacts — that make screenshots look grubby and logos look cheap. PNG has no such problem, because it does not approximate at all.
- Screenshots, especially of text, code or user interfaces.
- Logos, icons, charts and diagrams with flat colour.
- Anything that needs a transparent background, such as a logo placed over different colours.
- Working files you will edit and save again, where JPG would lose a little more each time.
For logos you control, SVG is better still: it is a vector format, so it stays sharp at any size and is often the smallest file of all.
Converting between them — what to expect
JPG to PNG stops any further loss, which is useful before editing, but it cannot restore detail the JPG already threw away. Expect the PNG to be noticeably larger than the JPG it came from, and do not expect it to look better. Any tool that promises JPG-to-PNG will improve quality is misleading you.
JPG to PNG also does not create transparency. A JPG has no transparency information to carry across, so every pixel stays opaque; to cut out a subject you need background removal instead.
PNG to JPG is where the big savings are, with one catch: JPG has no transparency, so transparent areas have to be filled with a solid colour. White is the usual choice for documents; choose a colour that matches wherever the image will sit.
For websites, consider WebP instead
If the image is going on a web page, the JPG-or-PNG question has a better answer. WebP handles both jobs: its lossy mode produces files typically 25–35% smaller than JPG at the same visual quality, and its lossless mode keeps transparency and is usually around a quarter smaller than PNG. Every current browser supports it.
PNG to WebP and JPG to WebP convert existing images, and the guide to image formats for websites covers WebP, AVIF and SVG in more detail. If you need to keep the format and just want smaller files, compress the images instead.