The short answer
- Photographs: JPG, or WebP if the destination supports it.
- Screenshots, diagrams, text and logos: PNG.
- Anything needing a transparent background: PNG or WebP. JPG cannot do transparency.
- Images on your own website: WebP is usually the smallest widely supported choice, with JPG or PNG as a fallback where needed.
The rest of this guide explains why, so you can handle the cases that do not fit neatly.
JPG: the photo workhorse
JPG (also written JPEG) uses lossy compression. It throws away detail that the eye is least likely to notice, mainly fine colour variations and subtle texture, and in return produces small files. Photographs, which are full of smooth gradients and natural noise, compress very well this way.
Its weaknesses are also well known. It has no transparency. Sharp edges and text develop faint halos or smudges called compression artifacts, especially at low quality. And every time you open and re-save a JPG, it is compressed again, which adds a bit more damage. Keep an original and always export from that, rather than saving a copy of a copy.
JPG is the safest format for compatibility: every browser, phone, email client, printer and upload form accepts it.
PNG: sharp edges and transparency
PNG is lossless. It stores the exact pixels, so there are no compression artifacts and you can re-save as often as you like with no quality loss. It also supports a full transparency channel, so a logo can sit on any background without a white box around it.
The cost is size. A photo saved as PNG can be several times larger than the same photo as a JPG, because PNG compresses by finding repeated patterns, and photographs have few. By contrast, screenshots, flat illustrations, icons and charts have large areas of identical colour, so PNG handles them efficiently and keeps text crisp.
If you need to remove a plain background and keep it transparent, our PNG transparency tool saves the result as a PNG.
WebP: smaller files for the web
WebP was designed by Google for the web and can work either way: it has a lossy mode that competes with JPG and a lossless mode that competes with PNG, and both support transparency. At similar visual quality, lossy WebP photos are commonly somewhere around a quarter to a third smaller than JPG, and lossless WebP is usually smaller than PNG. Exact savings depend on the picture.
Every current major browser can display WebP. The remaining friction is outside the browser: some older desktop programs, print services, email clients and upload forms still reject it. When you are posting to a site you do not control, check what it accepts. A newer format, AVIF, can compress even better but is slower to encode and less universally supported, so we leave it out here.
Because smaller images load faster, switching a website's photos from JPG to WebP is one of the cheaper ways to improve page speed.
Choosing by situation
| Situation | Best choice | Why |
|---|---|---|
| Photo for a blog or store | WebP (JPG fallback) | Small files, good quality |
| Photo to email or send to print | JPG | Accepted everywhere |
| Screenshot with text | PNG | Crisp edges, no artifacts |
| Logo on a coloured page | PNG or WebP | Transparency |
| Image you will keep editing | PNG (lossless) | No loss from re-saving |
| Simple icon or illustration | SVG if available, else PNG | Scales without blur |
Two more formats come up: GIF, which is limited to 256 colours and is mainly used for simple animation, and SVG, a vector format for logos and icons that stays sharp at any size. Neither replaces the three above for photos.
Converting safely
Converting between formats is easy, but it does not recover information that is already gone.
- JPG to PNG makes the file bigger and stops further loss, but the artifacts already baked in stay.
- PNG to JPG shrinks the file but discards detail permanently and removes transparency; transparent areas become a solid colour, usually white or black.
- JPG to WebP is a second lossy pass. For the best result, convert from the original rather than from a JPG that has already been saved at low quality.
The image format converter converts in your browser between PNG, JPG and WebP, with a quality setting for the lossy formats. If your goal is just a smaller file, try the image compressor first, since you may not need to change the format at all.
Because the tools run in your browser, your files are not uploaded anywhere.
Frequently asked questions
Is PNG better quality than JPG?
PNG is lossless, so it preserves exact pixels, but that does not make it better for photos. A well-exported JPG looks the same to most people at a much smaller size. PNG is better for screenshots, text and transparency.
Does WebP work everywhere?
It works in all current major browsers. Some older software, email clients and upload forms may not accept it, so check where the file is going or keep a JPG copy.
Why does my PNG have a white background after converting to JPG?
JPG cannot store transparency, so transparent areas must be filled with a solid colour, typically white. Keep the PNG or use WebP if you need transparency.
Will converting JPG to PNG improve the image?
No. It prevents more loss when re-saving but cannot restore detail already removed by the earlier JPG compression. The file will usually become larger.
Which format is best for printing?
High-quality JPG is the most commonly accepted for print uploads, and PNG works too. Pay more attention to resolution than to the format; print needs more pixels than a screen.