JPG vs PNG: the actual difference
JPG (or JPEG) is a lossy format. Every time you save a JPG, the encoder throws away pixel data it judges the human eye won't miss, in exchange for a much smaller file. That tradeoff is exactly right for photographs, where a few million subtly-wrong pixels are invisible at normal viewing size.
PNG is lossless. It compresses the file, but never discards any pixel data. Decompress a PNG and you get back the exact image that was encoded, pixel for pixel. PNG also supports an alpha channel, meaning parts of the image can be fully or partially transparent, something JPG cannot do at all.
So the real question is never "which format is better." It's: does this specific image need transparency or perfect pixel accuracy, or is it a photo where a small, invisible quality tradeoff buys a much smaller file?
When you should convert to PNG
- Logos and icons. Sharp edges and flat colors are exactly where JPG's compression artifacts show up as visible fuzz around edges. PNG keeps edges crisp.
- Screenshots. Text and UI elements have hard edges too. A JPG screenshot often looks slightly smudged around text; PNG doesn't.
- Anything that needs transparency. A logo that needs to sit on top of different colored backgrounds has to be PNG (or another format with alpha support like WebP).
- Images you'll edit again later. If a file is going to be re-opened, edited, and re-saved multiple times, PNG avoids the compounding quality loss that happens every time a JPG gets re-saved.
When PNG is the wrong choice
Don't convert to PNG by default. For photographs, most icons-with-lots-of-detail, and any image where file size matters more than pixel-perfect accuracy, PNG usually makes the file noticeably bigger for no visible benefit. A converted photo can easily go from 400KB to 3-4MB as a PNG. If you're publishing product photos, blog images, or anything bandwidth-sensitive, JPG (or the newer WebP format) is almost always the better call.
A useful rule of thumb: PNG for graphics with flat color and sharp edges, JPG for photographs, WebP when you can use it and want both efficiency and quality.
How to convert JPG to PNG for free
The conversion itself is simple: decode the JPG into raw pixels, then re-encode those pixels as PNG. No quality is lost in that step — whatever quality the original JPG already had is what you get, just stored losslessly from that point forward.
You can do this with desktop image editors, but for a one-off or a batch of files, a browser-based converter is faster and skips the "why do I need Photoshop for this" problem entirely. Our own free JPG to PNG converter does the whole thing using the browser's Canvas API: your image never leaves your device, there's no upload step, and it works on any file size or quantity.
Converting many images at once
If you're converting a handful of screenshots or a batch of icons exported from a design tool, look for a converter that accepts multiple files in one go rather than one-at-a-time uploads. That's the difference between a 30-second job and a 10-minute one when you have 20+ files. Our tool accepts multiple JPGs in a single selection and converts each one independently, with its own download link.
Common mistakes to avoid
- Converting a photo to PNG expecting better quality. It won't look any different, just take up more storage.
- Uploading sensitive images to an unknown "free converter" website. Check whether the tool actually processes files in your browser, or silently uploads them to a server first.
- Re-saving as JPG repeatedly during editing. Each JPG save re-compresses and loses a little more quality. Work in PNG (or your editor's native format) until the final export.