How to convert JPG to PNG
- Add the files. Drop one JPG or a batch on the box, click it to choose files, or paste an image you copied. Each file converts to PNG as soon as it is added.
- Check the sizes. Every row shows the JPG size, the PNG size and how many times bigger the PNG is, so nothing surprises you after the download.
- Download. Use the button on a row, or the ZIP button for two or more files. The name stays and only the extension changes:
logo.jpgbecomeslogo.png.
Nothing to install and no account. To go the other way, use the PNG to JPG converter.
Why the PNG is bigger than the JPG
JPG is a lossy format: when the file was saved, the encoder discarded fine detail the eye barely notices and stored the rest very compactly. That is why a photo can fit in a few hundred kilobytes. PNG is lossless: it records every pixel exactly as it is, using compression that works well on flat color and sharp edges but poorly on the grain, noise and gradients of a photograph.
When you convert a JPG to PNG, the PNG faithfully stores every pixel of the decoded JPG, including the small compression artefacts it already contains. Nothing is lost, but nothing is regained either, and the file usually comes out several times larger. Photos grow the most; a simple graphic saved as JPG grows less. The tool shows the exact figure for each of your files.
Converting does not improve quality. Detail that JPG compression removed when the file was first saved is gone for good. What PNG gives you is a copy that will not lose anything more, however many times you edit and save it.
When a PNG is worth it
| Situation | Convert to PNG? | Why |
|---|---|---|
| You will edit the image and save it several times | Yes | Each JPG save compresses again and adds loss. PNG saves are lossless. |
| A form, a template or design software requires PNG | Yes | The picture is unchanged, only the container is what the software expects. |
| Logo or graphic you plan to cut out | Yes, then remove the background | PNG can hold transparency once you erase the background in an editor. |
| Photo for email, a website or social media | No | The JPG is already smaller and looks the same. For a website, WebP is smaller still. |
| You want a transparent background | Not on its own | Converting keeps the background. It has to be removed in an editor. |
JPG, PNG and transparent backgrounds
JPG has no transparency, so the white or colored background around a logo saved as JPG is real pixels. PNG supports transparency, but converting cannot know which pixels are the background, so they stay exactly as they were. To get a transparent logo, remove the background in an image editor after converting, or better, ask whoever designed the logo for the original vector file (SVG, AI, EPS or PDF), from which a clean transparent PNG can be exported at any size with the SVG to PNG converter.
How to convert JPG to PNG without a tool
On Windows, open the JPG in Paint and choose File, Save as, PNG picture. On a Mac, open it in Preview, choose File, Export and pick PNG; to convert several, open them together, select all the thumbnails in the sidebar and choose Export Selected Images. Photoshop, GIMP and Affinity export PNG as well. A browser tool is quicker for a batch or on a computer where you cannot install anything.
Is it safe and private
The files never leave your device. The page decodes each JPG with your browser, draws it on a canvas and saves it with the browser's own PNG encoder, so there is no upload and no server queue, and it keeps working offline once loaded. Camera metadata such as EXIF and the GPS location of a photo is not copied into the PNG.
Methodology and limits
- Decoding
- Each file is opened by your browser as an image on your device. JPG works in every browser, and PNG, WebP, GIF, BMP and SVG work as well. HEIC usually opens only in Safari.
- Encoding
- The decoded pixels are drawn on a canvas the same size as the image and saved with the browser's own encoder (canvas toBlob) as PNG, which is always lossless. No resizing, sharpening or color change is applied.
- Size change
- Each row divides the PNG size by the JPG size, both measured from the files themselves.
- Orientation
- Current browsers apply the EXIF orientation of a phone photo when they decode it, so the PNG is saved the right way up.
- Sizes
- 1 KB = 1,024 bytes and 1 MB = 1,048,576 bytes, as Windows shows them. macOS divides by 1,000, so it shows the same file slightly larger.
- Limits
- Up to 50 files per batch, each up to 100 million pixels and 16,384 pixels on a side. Metadata (EXIF, GPS, XMP) and embedded color profiles are not copied, and colors are converted to sRGB. Large PNGs use a lot of memory: on a phone, convert big batches in smaller groups.
Sources
- Image file type and format guide, MDN Web Docs, on JPEG lossy and PNG lossless compression
- Portable Network Graphics (PNG) Specification (Third Edition), W3C
- ITU-T T.81, Digital compression and coding of continuous-tone still images, the JPEG standard, published by the W3C
- image-orientation, MDN Web Docs, on browsers applying EXIF orientation by default
- HTMLCanvasElement: toBlob() method, MDN Web Docs, the browser encoder this tool uses