JPEG is often a useful choice for compact photographs. PNG is useful when you need lossless image storage, crisp graphics or transparency. The better choice depends on the image and where it needs to go.
What you trade for a smaller file
Adobe’s comparison explains that JPEG commonly uses lossy compression: it discards some image information to reduce file size. PNG uses lossless compression. Ordinary JPEG files also lack PNG’s transparent-background support.
Lossless does not mean a picture automatically becomes sharp or detailed. Saving a blurry original in another format cannot create detail that was never there. Think of the format as a way to store the picture you have, not a repair service for the picture you wish you had.
Match the format to the task
MDN’s image-format guide distinguishes photographic compression from situations that need precise reproduction or transparency. It also covers newer formats such as WebP and AVIF, so JPEG and PNG are not the only options a website can serve.
For a quick practical choice, consider three imaginary files:
- A holiday photo for an email: try JPEG and inspect the exported result.
- A small logo that must sit over a colored background: check whether PNG’s transparency solves the problem.
- A screenshot of a table: inspect small text and lines carefully before accepting a smaller export.
Compare the actual exports
Keep your original. Export two copies, name them clearly, and compare both file size and appearance at the size the audience will see. Check fine lines, text and edges rather than judging only a zoomed-out preview.
That is a suggested workflow, not a measured benchmark. A file extension alone cannot tell you whether an export is suitable: dimensions, source quality and export settings still matter. Nor does changing the extension by renaming a file convert the underlying image.
Working on something visual? Explore creative projects from public archives. For another kind of compression, see what lossless audio means.
