JPG or PNG: what converting to PNG does, and what it cannot
What a JPG gains and loses as a PNG, measured on a photo and a screenshot, why the PNG is so much bigger, and when the conversion is worth it.
Last reviewed · 1,232 words
In short
- A PNG keeps exactly what the JPG holds. It cannot restore detail the JPG already lost, but nothing more is lost when the PNG is edited and saved again.
- Expect a much bigger file. Our 3,000 × 4,000 test photo went from 3.63 MB as JPG to 15.60 MB as PNG.
- Even a screenshot grows. Ours went from 305.0 KB as JPG to 1.04 MB as PNG, because JPG's faint noise around text is costly for PNG.
- A JPG has no transparency, so the PNG has the same solid background. Converting does not remove backgrounds.
- Nothing is uploaded. Files are converted in this browser tab.
Some forms, design tools and print templates ask for PNG. Some people convert to PNG hoping to make a blurry JPG sharper, or to get a transparent background. The first works exactly as you would hope; the second and third do not. This guide explains what converting JPG to PNG really does, with measurements from the converter above.
How to convert JPG to PNG
- Choose the JPG or JPEG files at the top of the page. One or up to 50 at once.
- Download each PNG, or all of them as one ZIP when there are several.
There are no settings to choose: PNG is lossless, so there is no quality slider. The pixel size stays exactly the same.
What changes, and what does not
A JPG stores a close approximation of a picture, made small by discarding detail the eye is unlikely to miss. A PNG stores every pixel exactly. Converting JPG to PNG takes the approximation the JPG holds and stores it exactly.
So the PNG looks identical to the JPG. Every pixel is the same as the browser showed it. Nothing is added: blur, blockiness or faint halos in the JPG are now faithfully preserved in the PNG.
What the PNG gives you is no further loss. Each time a JPG is opened, edited and saved as JPG again, it is compressed again and loses a little more. A PNG can be edited and saved a hundred times without any change you did not make. That is why designers convert to PNG before editing, and convert to JPG only once at the end.
Why the PNG is so much bigger
We converted two test images, both saved as JPG at 92% quality:
| Test image | Pixels | JPG | PNG | Change |
|---|---|---|---|---|
| Grainy phone-style photo | 3,000 × 4,000 | 3.63 MB | 15.60 MB | about 4.3 times larger |
| Screenshot with text | 1,920 × 1,080 | 305.0 KB | 1.04 MB | about 3.5 times larger |
A photo has millions of slightly different pixels, and PNG must record each one exactly. Its compression works by finding repeats, and a photo has few. Four times larger is typical; sometimes more.
The screenshot grew too, which surprises people, because screenshots are usually PNG's home ground. The reason is the JPG step it went through: JPG leaves faint speckles of noise around every letter, and those speckles are not repeats, so PNG has to store each one. A screenshot captured straight to PNG would have been far smaller than this. If you have the original screenshot, keep that PNG; converting a JPG of it gives you the worst of both.
Each conversion took about half a second to a second on a desktop browser.
JPG to PNG does not make a background transparent
A JPG has no transparency, so there is no see-through area to carry into the PNG. The white wall behind a product photo, or the paper behind a signature, stays in the PNG as solid white.
Making a background transparent means deciding, pixel by pixel, what is subject and what is background: background removal. That is a different job from changing the format. For a signature on white paper, the Signature Resize tool cleans the paper to pure white, which is what most forms want anyway.
When converting to PNG is worth it
- A form, template or tool asks for PNG. Some design tools, app stores and print templates take only PNG.
- You are about to edit the picture. Convert once, edit the PNG as often as you like, and save the final JPG once.
- The picture is a chart, logo or diagram that you will reuse at the same size. PNG keeps its edges exactly from now on.
When to stay with JPG
- You want a smaller file. PNG will be several times larger; email and upload limits will bite.
- The form accepts JPG. There is no quality to gain, only size to lose.
- You hoped for a sharper picture. The PNG is exactly as sharp as the JPG, no more.
To go the other way, the PNG to JPG Converter turns PNGs into JPGs at a chosen quality.
Is JPEG the same as JPG?
Yes. JPEG, the Joint Photographic Experts Group, is the name of the format. Its file extension was written .jpg on older Windows systems, which allowed only three letters, and .jpeg elsewhere. Both are the same format, and both convert the same way here.
Converting many photos at once
Choose up to 50 JPGs in one go: hold Ctrl (Cmd on a Mac) to pick several in the file dialog, or press Ctrl + A to take a whole folder. They are converted one after another rather than all at once, so a phone does not run out of memory on a large batch. Each photo shows its result as soon as it is ready, with the size before and after.
With two or more done, Download all as ZIP saves every PNG in one file, each with its original name and .png at the end. Two photos with the same name become "name.png" and "name (2).png" inside the ZIP instead of one replacing the other.
Remember the size: fifty phone photos as PNG can easily come to several hundred megabytes. If the PNGs are for editing, convert only the ones you will edit.
JPG to PNG on a phone
The page works in a phone browser too. Tap the file button and pick from the gallery or Files; Android allows several at once. The PNGs download to the phone's Downloads folder. Because PNG files are large, check the phone has free space before converting a big batch, and convert a few at a time if it is nearly full.
Editing without losing quality
The reason to convert before editing is easiest to see with a simple experiment. Open a JPG, add a line of text, and save it as JPG. Do it again, and again. After a dozen rounds the edges of the text grow faint halos and flat colours develop blotches, because each save compresses the whole picture again. Do the same with a PNG, and the twelfth version is pixel for pixel what you made.
So the workflow that keeps quality is: convert the JPG to PNG once, make every edit on the PNG, and export a JPG only at the very end if the place you are sending it to needs JPG. The picture then goes through JPG compression one more time in total, rather than once per edit.
Converting other formats to PNG
The converter accepts any image your browser can open: WebP, GIF, BMP and AVIF as well as JPG. A WebP or a PNG with transparency keeps its transparency in the PNG, since PNG can store it. An animated GIF or WebP gives a PNG of its first frame.
What this tool assumes
- Each image is decoded by your browser and saved as a PNG at exactly the same pixel size, with no further loss.
- JPGs have no transparency, so the PNGs are fully opaque. Other image types are accepted too, and a PNG or WebP with transparency keeps it.
- Images up to 50 megapixels are converted, up to 50 files at a time, one after another, with a ZIP for several.
- The files stay on your device. The PNGs carry none of the camera or location details of the originals.