JPG: the standard for photos
JPG uses lossy compression and is designed for photographs and other images with smooth colour changes. It is supported almost everywhere, from old phones to print shops. It does not support transparency, and repeated re-saving gradually lowers quality. Sharp text and thin lines can show fuzzy edges at low quality settings. Because it is so widely supported, JPG is often the safe choice when you do not know what software the other person uses.
PNG: sharp graphics and transparency
PNG is lossless and supports transparent backgrounds. It is ideal for logos, icons, screenshots and anything with text or flat colour. For photographs the files are usually much larger than JPG, because photos contain millions of slightly different colours that lossless compression cannot shrink much.
WebP: smaller files, modern support
WebP can be lossy or lossless and supports transparency. At similar visual quality, WebP files are often noticeably smaller than JPG or PNG. Current major browsers can display WebP. Some older software, image editors and email programs may not open it, so check where the file will be used. Lossy WebP is a good fit for photos, while lossless WebP is an alternative to PNG for graphics. Exact savings depend on the image, so test your own files rather than expecting a fixed percentage.
Animation is another point. GIF, WebP and PNG variants can all hold moving images in some form, but support differs between programs, so test before relying on it.
Finally, think about file size against purpose. A photo that fills a whole screen justifies more bytes than a small thumbnail, whichever format you choose.
Quick guide
- Photo on a website: WebP, or JPG if you need maximum compatibility
- Logo or icon with transparency: PNG or WebP
- Screenshot with text: PNG
- Image you will keep editing: PNG (lossless), not JPG
- Sending to someone with old software: JPG
Worked examples
A product photo with a plain background, shown on a shop page: use WebP or JPG at about 80% quality. The file is usually far smaller than the same picture as PNG.
A company logo with a transparent background that sits on both white and dark pages: use PNG or WebP, because JPG would add a solid background.
A screenshot of a settings screen with small text: use PNG so the letters stay crisp. A lossy format may blur them slightly.
A photo you will send to a printer or a relative with an older computer: use JPG for the widest support.
An icon with a soft shadow on a transparent background: PNG or WebP keeps the smooth transparency of the shadow, while JPG cannot.
Step-by-step: choosing a format
- Ask whether the image needs transparency. If yes, choose PNG or WebP.
- If it is a photo, choose WebP or JPG.
- If it is flat colour, text or line art, choose PNG or lossless WebP.
- Think about where it will be opened. Unsure? JPG and PNG are the safest.
- Convert from your best original and compare the result.
- Keep the original file in case you need a different format later.
Converting between formats
Converting does not add detail that is already lost. Turning a low-quality JPG into PNG makes a bigger file, not a better picture. Convert from the best original you have, and choose the target format for how the image will be used. Converting a PNG with transparency to JPG replaces the transparent area with a solid colour, so keep the PNG as well. The original stays as it was when you convert, so keeping both costs you nothing but disk space.
Common mistakes
- Saving photos as PNG and wondering why pages are slow.
- Using JPG for logos and getting fuzzy edges or a white box.
- Converting JPG to PNG expecting better quality.
- Editing and re-saving a JPG many times instead of keeping a lossless master.
- Using WebP for a file that must be opened by very old software.
- Renaming a file extension by hand instead of converting it properly, which does not change the real format.
Convert privately with DoneImg
DoneImg has converters for JPG, PNG and WebP that run in your browser, so nothing is uploaded. Pick the converter, add your image, choose the target format and download it. For photos you can also adjust the quality to balance size and sharpness.
Which format is best overall?
There is no single winner. Match the format to the content and to the software that will open it.