How to convert PNG to JPG
- Add the files. Drop one PNG or a batch on the box, click it to choose files, or paste a screenshot straight from the clipboard. Each row shows the size in pixels and the original weight.
- Set the quality and the background. 92 is the default and keeps a photo visually the same. Lower it for smaller files. If the PNG has transparent areas, pick the color that fills them: white suits documents and most forms.
- Download. Each row has its own button and shows how much smaller the JPG is. With two or more files, one button gives you a ZIP.
team-photo.pngbecomesteam-photo.jpg.
Nothing to install, no account and no watermark. To shrink images for a website instead, the image optimizer also converts to WebP and AVIF and resizes.
When JPG is the better format
PNG is lossless: it stores every pixel exactly. That is ideal for screenshots, logos and graphics with flat color, but a photograph saved as PNG is usually several times the size of the same photo as a JPG, with no difference you can see. Phones, screenshot tools and design apps often save photos as PNG anyway, which is how a single picture ends up too big for an email or an upload form.
| Your image | Choose | Why |
|---|---|---|
| Photograph, product shot, scanned picture | JPG | Much smaller file, and the compression is designed for continuous tone like skin, sky and texture. |
| Image for email, a form with a size limit or a print shop | JPG | Accepted almost everywhere and light enough to attach. |
| Logo, icon or cutout with a transparent background | Keep PNG | JPG cannot be transparent, so the background becomes a solid color. |
| Screenshot with text, chart, diagram | Keep PNG | JPG compression leaves soft halos around sharp edges and small text. |
| Image for a website | WebP | Smaller than both, and every current browser displays it. Use the image optimizer. |
The tool measures the result rather than guessing: every row shows the PNG size, the JPG size and the difference, so you can tell at once whether the conversion was worth it. Flat graphics sometimes shrink very little, which is a sign they belong in PNG.
What happens to transparency
JPG has no alpha channel, so a transparent pixel cannot exist in it. Before encoding, this tool paints every transparent area with the color you choose, and semi-transparent edges, such as the soft outline of a cutout, blend into that color. White is the default because most documents and forms are white. If the image will sit on a dark website, a colored slide or a brand background, pick that exact color with the picker so the edges look clean on it. If it must stay transparent, it must stay a PNG (or become a WebP).
JPG quality: which number to use
The slider sets how much detail JPEG compression may discard. 85 to 94 suits nearly everything: email, documents, social posts and upload forms, with no visible change at normal size. 95 to 100 is for print and for an image you will edit again, at a much larger size. 70 to 84 makes noticeably smaller files and is fine for thumbnails, though smooth gradients and fine detail start to show blocks. The numbers are this browser's scale: 90 here is not the same file as 90 in Photoshop.
JPG is lossy every time it is saved. Keep the original PNG if you will edit the image again, and convert a fresh copy from it each time rather than re-saving a JPG.
How to convert PNG to JPG without a tool
On Windows, open the PNG in Paint and choose File, Save as, JPEG picture (transparent areas turn white). On a Mac, open it in Preview, choose File, Export, pick JPEG and set the quality; for a batch, open the files together, select all the thumbnails in the sidebar and choose Export Selected Images. Any photo editor exports JPG too. The browser tool is quicker when you have many files or cannot install software.
Is it safe and private
The files never leave your device. The page reads each PNG with your browser, draws it on a canvas and saves it with the browser's own JPEG encoder, so there is no upload and no queue, and it keeps working offline once loaded. Metadata stored in the PNG, such as text chunks or a camera's EXIF block, is not copied to the JPG.
Methodology and limits
- Decoding
- Each file is opened by your browser as an image on your device. PNG works in every browser, and WebP, JPG, GIF, BMP and SVG work as well. HEIC usually opens only in Safari.
- Encoding
- A canvas the size of the image is filled with your chosen color, the PNG is drawn on top, and the result is saved with the browser's own encoder (canvas toBlob) as JPEG at the quality you set, divided by 100.
- Size change
- Each row compares the original file size with the new one, measured from the files themselves.
- Animation
- An animated PNG shows only its first frame in the result.
- 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 and embedded color profiles are not copied, and colors are converted to sRGB. On a phone, convert large batches in smaller groups.
Sources
- Image file type and format guide, MDN Web Docs, on PNG and JPEG, their compression and transparency
- 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
- HTMLCanvasElement: toBlob() method, MDN Web Docs, the browser encoder and its quality argument