Converting a JPG to PNG is mostly about what happens next. PNG is lossless, so once a photo is in PNG form you can crop, annotate and save it repeatedly without each save adding another round of JPG compression. It is also the format some upload forms, design tools and print templates insist on. This page opens with PNG as the output, so you drop the JPGs and convert. It is worth being clear about what conversion does not do. It does not improve the image: any blockiness or blur already in the JPG is preserved exactly. The PNG will also be larger, often several times, because PNG compression is built for flat graphics rather than photos. And it does not make the background transparent. PNG supports transparency, but a JPG never had any, so the white or coloured background stays until you remove it in an editor and save again as PNG. If the only goal is a smaller or more modern file, WebP is the better choice. The converter handles batches and can resize at the same time if the full resolution is not needed. To go back the other way use PNG to JPG Converter, and for web use see JPG to WebP Converter.
Choosing the right image format for web use has a significant impact on file size and quality. JPEG (Joint Photographic Experts Group) uses lossy compression optimized for photographs: it discards subtle color gradients in ways the human eye does not easily notice, achieving compression ratios of 10:1 to 20:1 at acceptable quality. PNG (Portable Network Graphics) uses lossless compression and supports full transparency (alpha channel), making it ideal for logos, icons, screenshots, and images with sharp edges or text. WebP is Google's modern format that achieves better compression than both JPEG and PNG at equivalent quality: typically 25 to 35 percent smaller than JPEG at the same quality setting, and 26 percent smaller than PNG for lossless images. WebP also supports transparency like PNG. GIF (Graphics Interchange Format) is the oldest format still in use, primarily kept alive by its support for animation. For still images, GIF is inferior to PNG in both quality and compression, limited to 256 colors per frame. Converting to WebP for web delivery is the most impactful single optimization for image-heavy sites. Browser support for WebP is now essentially universal (Chrome, Firefox, Safari 14+, Edge). For cases where legacy Safari support is required, serving WebP via a picture element with a JPEG fallback provides the best result across all browsers.