When to Convert PNG to JPG (And When That's the Wrong Move)

Yes, always — but how much depends on the content and the quality setting. JPG uses lossy compression, which permanently discards image data to reduce file size. For photographs, the loss at quality 80–90 is generally invisible to the human eye. For images with sharp edges, text, logos, or solid colors, JPG artifacts become visible — you'll see faint halos around edges and color banding. Converting back to PNG afterward doesn't restore lost quality; you're just converting the degraded JPG data into a lossless format, which gets you a large PNG of a lower-quality image.

You can convert the file, but you can't recover information that was discarded when the JPG was created. A JPG-to-PNG conversion gives you a lossless copy of the already-compressed JPG — the PNG won't have JPG's ongoing compression artifacts with further editing, which is the main reason to do this conversion. But the original quality loss is permanent. This is why source files should always be kept as PNGs or RAW files if you might need to edit them later.

It depends on the image type. JPG is consistently better for photographs — smaller files with imperceptible quality difference. PNG is better for logos, icons, screenshots, and images with text. WebP is better than both for web use — it's smaller than JPG at equivalent quality and supports transparency like PNG. Most modern browsers support WebP. If you're optimizing for web performance, serving WebP with PNG/JPG fallbacks is the current best practice.

PNG is lossless — it stores every pixel exactly. JPG is lossy — it discards some data to achieve compression. For photographs with millions of subtly different colors, JPG compression is extremely efficient, often 5–10x smaller than PNG at similar visual quality. PNG compression works by finding patterns in pixel data, which is efficient for simple images but not for the complex color variations in photos. A 5MB photo as PNG might be 400KB as JPG at 85% quality.