Most image problems come down to using the wrong format: a logo with fuzzy edges, a screenshot that weighs several megabytes, or a photo an upload form refuses. JPG, PNG and WebP are all good formats. They are simply good at different things.
The quick answer
| You have | Use | Why |
|---|---|---|
| A photograph for a website | WebP (or JPG) | Smallest file for natural images |
| A photograph to email or upload to a form | JPG | Accepted everywhere |
| A screenshot with text | PNG or lossless WebP | Keeps text and edges crisp |
| A logo or icon with transparency | SVG, otherwise PNG or WebP | Transparency and sharp edges |
| An image you will keep editing | PNG (or the editor's own format) | No quality loss on each save |
JPG: small files for photographs
JPG (also written JPEG) uses lossy compression. It throws away detail the eye is least likely to notice, which is why a photo can shrink to a tenth of its raw size and still look fine. The compression is tuned for smooth, natural images.
That tuning is also its weakness. On sharp edges, such as text, line art and flat-colour logos, JPG produces a faint smudgy halo. JPG also has no transparency, and every time you edit and re-save a JPG it is compressed again, losing a little more each time.
PNG: exact pixels and transparency
PNG is lossless: what you save is exactly what you get back. It handles sharp edges perfectly and supports full transparency, which makes it the traditional choice for screenshots, diagrams, icons and logos.
The cost is size. PNG compresses flat colours very well, but a photograph saved as PNG can easily be five to ten times larger than the same photo as a good-quality JPG, with no visible benefit.
WebP: the modern all-rounder
WebP was developed by Google for the web. It can work in a lossy mode (like JPG) or a lossless mode (like PNG), and supports transparency and animation in both. In lossy mode it generally produces smaller files than JPG at comparable quality; in lossless mode, smaller files than PNG.
All current versions of Chrome, Edge, Firefox and Safari display WebP. The remaining gaps are outside the browser: some older desktop programs, some print services and some upload forms still expect JPG or PNG. If one of those rejects your file, convert it with the Image Converter.
What about AVIF and HEIC?
AVIF is a newer format that often beats WebP on file size and is now supported by the major browsers, though it is slower to create and less widely accepted by other software. HEIC is what iPhones use for photos; it is efficient but poorly supported on the web and on older Windows systems. Our guide to converting HEIC to JPG covers that case.
A simple rule to remember
- Photo? WebP for your own website, JPG for everything else.
- Text, sharp edges or transparency? PNG, or WebP if it is for the web.
- File too big? Reduce the pixel dimensions first, then the quality. The Image Compressor does both.
Once the format is right, the next step is getting the size down without visible damage, which is covered in how to compress images for a website.
Frequently asked questions
Is WebP better than JPG?
For websites, usually yes: WebP files are typically smaller at similar visual quality and also support transparency. JPG is still the safer choice when a file has to open in old software or be accepted by an upload form that only lists JPG.
Does converting JPG to PNG improve quality?
No. PNG stores exactly what it is given, so it preserves the JPG's existing compression artefacts in a much larger file. Convert to PNG only if you are going to edit and re-save the image repeatedly.
Which format is best for a logo?
SVG if you have a vector version, because it stays sharp at any size. Otherwise use PNG or WebP with a transparent background.