Not sure whether to use JPG, PNG, or WebP? Learn what each format is best for, how to convert between them, and how to pick the right one for web, print, or sharing.
By Ernzi Tools team · November 6, 2026
JPG, PNG, and WebP all store pictures, but they were designed for different jobs — and picking the wrong one can mean a file ten times larger than necessary, or a transparent logo with an ugly white box around it. The good news is that converting between them takes seconds in a browser, and once you know the strengths of each format, the choice becomes obvious.
JPG (or JPEG) is the classic photo format. It uses lossy compression tuned for the smooth color gradients found in photographs, which is why a 5 MB camera photo can become a 300 KB JPG with no visible difference. JPG does not support transparency, and it is a poor choice for sharp text or line art, where its compression creates visible smudges around edges. Use JPG for photos, product shots, and anything with lots of colors and soft transitions.
PNG uses lossless compression, so every pixel is preserved exactly. It supports full transparency, which makes it the right format for logos, icons, screenshots with text, and any image that needs a see-through background. The trade-off is size: a photographic PNG can be several times larger than the same image as a JPG. Use PNG when quality and transparency matter more than file size.
WebP is the newer format from Google, and it combines the best of both: lossy compression like JPG, lossless mode like PNG, and transparency like PNG. In practice, WebP files are 25–35% smaller than JPGs at the same quality, and much smaller than PNGs for photos. All modern browsers support it. The only reason not to use WebP is compatibility with very old software — if your audience might open files in an ancient image viewer, stick with JPG or PNG.
Converting a whole folder of images follows the same rules as converting one, with one extra consideration: consistency. If you are converting product photos for a website, convert them all to the same format and roughly the same dimensions, so every page loads at the same speed and every image looks like it belongs to the same set. Process the images in small batches and check the first few results before doing the rest — if a setting is wrong, you want to discover it on three files, not three hundred.
JPG, PNG, and WebP cover most everyday needs, but you will meet other formats too. GIF is an old format that survives for one reason: simple animation. It only supports 256 colors, so it is terrible for photos, but perfect for short looping animations and tiny graphics. TIFF is a heavyweight format used in print and professional photography; it preserves maximum quality, but files are huge and browsers do not display it. BMP is an uncompressed Windows format with no real advantage today — if you find one, convert it to PNG and save most of the space. AVIF is the newest option, beating WebP on compression by another 20–30% with transparency and HDR support, and it now works in all modern browsers. The practical rule is simple: use WebP for the web, PNG for graphics, JPG for maximum compatibility, and AVIF when you control the whole pipeline.
Images destined for print follow different rules. A screen shows about 72–96 pixels per inch, so a 1200-pixel image looks large on a monitor but prints at only a few inches wide. For print, you want 300 DPI, which means a 4-by-6-inch photo needs roughly 1200 by 1800 pixels at minimum. Color matters too: screens use RGB, while printers use CMYK, and colors can shift noticeably between the two — bright blues and greens are the usual victims. For print, keep the image in PNG or TIFF at high quality and let the print shop handle the color conversion. For screens, WebP or JPEG at 72–96 DPI is all you need, and anything more just wastes bandwidth.
Yes, but every lossy step costs quality. Converting a PNG to a JPG throws detail away; converting that JPG back to PNG does not bring it back — it just wraps the same damaged pixels in a bigger file. The safe workflow is to keep one master copy in the highest quality format you have, usually PNG or the camera original, and generate JPG or WebP versions from it whenever you need them. That way you can always go back to the source and make a fresh conversion instead of stacking losses on losses.
One last tip: always convert from the original, highest-quality file you have. Converting a heavily compressed JPG into a PNG does not restore the detail that was already thrown away — it just makes a bigger file with the same flaws.
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