Tool guide
JPEG, WebP or PNG: which format to use
Every image you save has to pick a format, and the three you meet most are JPEG, PNG and WebP. They are not interchangeable. The wrong one makes a file several times larger than it needs to be, or fails to open where you send it.
The one idea that matters: lossy or lossless
Lossy formats make a file smaller by throwing away detail your eye is unlikely to notice. Lossless formats keep every pixel exactly and shrink the file only by storing it more cleverly.
- JPEG is lossy.
- PNG is lossless.
- WebP can be either. It has a lossy mode and a lossless mode.
Lossy shrinking works very well on photos, where nearby pixels are close but not identical. It works badly on sharp edges, where the discarded detail shows as fuzz around letters and lines.
JPEG: the safe choice for photos
JPEG has been around for decades, and nearly every phone, form, printer, email program and website accepts it. At sensible quality a photo looks fine and weighs a fraction of the original.
Its limits are plain. It cannot hold transparency. It leaves faint blotches around text and sharp lines. And each time you open, change and save a JPEG, it is compressed again and loses a little more. Keep your original, and make your copies from it.
Pick JPEG when the image is a photo and you need it to work everywhere, including forms with a size limit.
PNG: exact pixels and transparency
PNG keeps every pixel as it was and supports transparent areas. That makes it right for:
- screenshots and anything with text
- logos, icons and diagrams with flat colors
- graphics that need a see-through background
It is the wrong choice for photos. A photo saved as PNG is often several times the size of the same photo as JPEG, and the extra size buys nothing you can see. If a form rejects your photo for being too big and it is a PNG, switching to JPEG is often the quickest fix.
Pick PNG when sharpness matters more than size, or when you need transparency.
WebP: smaller, with a caveat
WebP was designed for the web. It can do what JPEG does, what PNG does and transparency too, and at similar quality its files are usually smaller. A WebP photo is often noticeably lighter than its JPEG equivalent.
The caveat is where it is accepted. Current browsers open it, but some older forms, editing programs, printers and upload pages still reject it, and it can fail in places you cannot predict. If a form lists accepted types and WebP is not among them, believe the form.
Pick WebP when you control where the file ends up, such as your own site, or when a form says it accepts it and you need the smallest result.
A quick note on HEIC
Many phones save photos as HEIC by default, a compact format that older software and many websites cannot open. If a site rejects your phone photo, this is a common reason. Share or export the photo as JPEG, or convert it with the HEIC to JPG tool, and try again.
Which should you choose?
| You have | Choose |
|---|---|
| A photo for a form or email | JPEG |
| A photo for your own web page, where size matters | WebP, or JPEG if unsure |
| A screenshot or a page of text | PNG |
| A logo or graphic with a see-through background | PNG, or WebP |
| A file for a form that does not list WebP | JPEG |
If you are not sure, JPEG is the one that fails least often.
Changing format and size
The photo compressor saves as JPEG or WebP at the size you ask for, so it suits photos but not PNG graphics. It does not make PNGs. To change a photo’s pixel size or save as PNG, JPEG or WebP, use the image resizer. If the limit is a number of kilobytes, read how to get a photo under a file size limit.
Both tools run in your browser and nothing is uploaded.
Questions
Is WebP better than JPEG?
For file size, usually yes: it makes smaller files at similar quality. For compatibility, no. Some older forms, programs and printers do not accept it, and JPEG is accepted nearly everywhere.
Why is my PNG screenshot so much bigger than a JPEG?
PNG keeps every pixel exactly. That suits flat colors and sharp text, but a photo has millions of slightly different colors, which makes lossless files large. JPEG shrinks them by discarding detail you can hardly see.
Does saving a JPEG again lose quality?
Yes, a little each time, because every save re-compresses the picture. Keep one good original and make copies from it rather than editing the same JPEG over and over.
Can JPEG have a transparent background?
No. JPEG has no transparency. If you need see-through areas, use PNG or WebP.
What is HEIC?
It is the format many phones save photos in by default. It is efficient but poorly supported by older software and websites, so people often convert photos to JPEG before sharing.