The short answer to JPG vs PNG: use JPG for photographs and PNG for everything else, such as screenshots, logos, diagrams and anything with text or a see-through background. JPG makes photos small by dropping detail you will not notice. PNG keeps every pixel, which keeps text sharp but makes photos heavy.
- Photographs: JPG. In our test, the same photo was ten times bigger as a PNG.
- Screenshots, logos, diagrams and text: PNG. The edges stay crisp and the file stays reasonable.
- A transparent background: PNG, always. JPG cannot store transparency at all.
What is the difference between JPG and PNG?
The difference between JPG and PNG is what each one is willing to throw away. JPG, also written JPEG, is lossy: the JPEG standard defines a lossy format, which saves space by leaving out fine detail and colour your eye is unlikely to miss. That is how it gets photos small.
PNG is lossless. The W3C PNG specification describes it as lossless storage with an optional alpha channel, the part of the file that records how see-through each pixel is. The picture you open is exactly the picture that was saved.
| JPG (JPEG) | PNG | |
|---|---|---|
| Compression | Lossy: leaves out detail to save space | Lossless: keeps every pixel |
| Transparency | None | Yes, fully or partly see-through |
| Best for | Photographs | Screenshots, logos, diagrams and text |
| Our test photo | 1.7 MB | 17.4 MB |
| Editing and saving again | Each save can lose a little more | Saves again without any loss |
| File extensions | .jpg and .jpeg, the same format | .png |
Those sizes come from one real photograph: a NASA picture of diggers rebuilding sand dunes at Kennedy Space Center, all sand and sky. We reduced it to 4,000 × 2,667 pixels and saved it both ways. The PNG came to 17.4 MB. The JPG, at quality 80, came to 1.7 MB: roughly a tenth of the size. Side by side at full size, we could not see a difference.
A screenshot tells a different story. A settings screen of text and buttons, saved the same two ways, came to 98 KB as a PNG and 78 KB as a JPG. The JPG saves little, and its letters are no longer exact copies of the original.
Which is better for photos, screenshots and logos?
Neither format is better in general. On quality, PNG vs JPG is no contest: PNG keeps every pixel. On size, it is no contest the other way for photographs. So whether to save a picture as PNG or JPG depends on what is in it:
- Photograph, no text: JPG, and the file will be roughly a tenth the size.
- Screenshot, diagram, logo, anything with text: PNG, and the edges stay crisp.
- Needs a transparent background: PNG, always. JPG cannot do transparency at all.
- A still from a video: the same rule. A filmed scene is a photograph, so save the frame with MP4 to JPG; a screen recording or on-screen text is a screenshot, so use MP4 to PNG.
- A page from a PDF: the same rule again. A page of text or diagrams stays sharpest as a PNG, so convert PDF to PNG; a scanned photo or a page full of pictures is smaller as a JPG, so convert PDF to JPG.
- Going on a website you control: WebP. The WebP documentation from Google puts it at 25 to 34% smaller than a JPG of the same quality, and 26% smaller than a PNG when both are lossless.
Turning a PNG into WebP takes a few seconds: convert PNG to WebP in your browser, and any transparency comes with it.
One case where the answer is neither: several photos that must arrive as one document, such as scanned forms or a set of receipts. JPG to PDF puts them in one PDF, each picture on its own page.
Another case for neither: a logo that must stay sharp at any size belongs in an SVG, which stores shapes rather than pixels (raster vs vector explains the difference).
Why does a photo saved as PNG get so big?
JPEG throws away detail your eye does not miss, which works beautifully on the gradual variation of a photograph and badly on the hard edges of text. PNG keeps every pixel exactly, which is right for a screenshot of an interface and enormously wasteful for a beach.
This is the difference between PNG and JPG at work. A photo is full of tiny variations, grain and sand and sky shifting shade by shade, and PNG has to record every one of them, so it barely shrinks. How JPG decides what to leave out is the subject of lossy vs lossless compression.
If a picture must stay a PNG, a PNG compressor can still shrink it in two ways. Lossless keeps every pixel and only packs the file better. Fewer colours makes it much smaller by using a limited set of colours. Both keep the transparency.
If it is a photo that is already a JPG and still too big, you can compress JPEG photos further. Lower the Quality, compare the result with the original side by side, and save when it still looks right.
What changes when you convert PNG to JPG, or JPG to PNG?
Converting between the two is quick, but it is not neutral. On Whatafile both conversions run in your browser, so the picture is not uploaded, and each one changes something you should know about first.
PNG to JPG: transparent areas turn white
JPG cannot store transparency, so a converter has to fill the see-through parts with a colour. On PNG to JPG, that colour is white. If your logo comes back on a white rectangle, this is what happened, and the fix is to send the PNG instead. Camera and location details stored in the file are left out of the JPG as well.
If the PNG is gone and all you have is a JPG of a logo on white, you can make the background transparent again by removing that one plain colour, then save the result as a PNG.
JPG to PNG: no lost detail comes back
When you convert JPG to PNG, the PNG copies the JPG pixel for pixel, compression marks included, and keeps a solid background, since a JPG has no transparency to pass on. What you gain is that later edits and saves stop losing quality, which they would as a JPG. That makes the PNG a sensible working copy for a picture you will edit several times.
Worth knowing
Converting a JPEG to PNG does not restore the detail JPEG discarded. It just stores the discarded version losslessly, in a bigger file.
JPG and PNG questions
Which is better, JPG or PNG?
Neither, in general. JPG is better for photographs, because the file is far smaller and the loss is hard to see. PNG is better for screenshots, logos, text and anything with a transparent background, because it keeps every pixel.
Is PNG higher quality than JPG?
PNG is lossless, so it keeps every pixel, while JPG leaves out some detail to save space. But converting a JPG to PNG does not bring that detail back: the PNG copies the JPG exactly, marks and all.
Why does my logo get a white background when I save it as JPG?
JPG cannot store transparency, so the transparent parts have to be filled with a colour, and Whatafile fills them with white by default. Keep the PNG if you need a see-through background.
Are JPG and JPEG the same format?
Yes: one format, two file extensions. A file ending in .jpg and one ending in .jpeg open in the same programs, and renaming one to the other changes nothing inside it. JPG vs JPEG explains why both endings exist.
Is a JPG or a PNG smaller?
For a photo, the JPG, by far: our test photo was 1.7 MB as a JPG and 17.4 MB as a PNG. For a screenshot the gap is small, 78 KB against 98 KB in our test, so the PNG costs little and keeps the text exact.