When PNG to JPG is a good idea
PNG keeps every pixel, which is wasteful for photographs. A photo saved as PNG, for instance from a screenshot or an export with the wrong setting, can be many times bigger than the same picture as a JPG with no visible difference.
- Upload forms, email and websites that limit file size or only accept JPG.
- Large photos that are slowing down a page or filling up storage.
- Sharing pictures with people or software that handle JPG more reliably than PNG.
What you give up
- Transparency. JPG has no transparent pixels. Everything see-through is blended onto the background colour you choose before the file is saved, so soft edges blend into that colour too.
- Exact pixels. JPG is lossy. Photos hold up well, but sharp text, thin lines and flat colours can pick up fuzzy artefacts around their edges, especially at low quality.
- Size, sometimes. A screenshot of text or a logo with few colours often compresses very well as PNG. As a JPG it can be larger and look worse. If the list shows a file getting bigger, keep the PNG, or try PNG to WebP.
Choosing quality and background
Around 90 is a safe default for photos. Between 80 and 90 files get noticeably smaller with little visible change. Below about 75 you may begin to see blocks and smudges, especially in smooth skies and around text. Because JPG is lossy, keep your original PNG instead of converting the JPG back to PNG later.
For the background, white suits most pictures. Choose black or a custom colour when the artwork is light on a transparent background, such as a white logo, which would disappear against white.